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73
Condensate Return Pumps
Stand Alone Pressure Motive Pumps
PUMPS
The stand alone Pressure Motive Pump (PMP) consists of the pump tank, the internal 76-89
operating mechanism, and a set of inlet and outlet check valves. Depending on the
particular model, pump tanks can be made from Ductile Iron, Fabricated Steel or
Stainless Steel. In most installations an additional receiver or reservoir tank and possibly
a high capacity steam trap may be required to complete the system.
tandardized Simplex, Duplex, Triplex, and Quadraplex packaged
S
systems include the Stand Alone Pumps and check valves with receiver
tank mounted on a steel base and frame. Multiple pumping units can
be used for increased capacity or for system redundancy. The units are
available in Ductile Iron, Carbon Steel and Stainless Steel.
Additional options such as sight glasses, insulation jackets, cycle counters,
motive and vent piping, pressure regulators, steam traps, strainers and
ASME code stamps, etc., are available.
Pump & Trap Combinations
Models PMPT & WPT92-97
Pump & trap combinations are used for draining condensate
from a single piece of heat transfer equipment. Model PMPT
has an internal steam trap inside the pump body. The WPT Series
have an appropriately sized external steam trap attached to the
pump and are mounted on a common base.
Watson McDaniel’s fully equipped ASME qualified fabrication facility110-111
stands ready to assist you with all your fabrication needs. Our engineering
staff specializes in the design of pressure motive condensate pumping
systems for both industrial and institutional applications. We offer either
standard packages, or specialized systems to meet your specific needs.
Electric Condensate Pumps
Models W4100 & W4200 112-115
Electric condensate pumps are available for condensate temperatures up
to 190
F. Carbon Steel and Cast Iron Tanks available. Available options include
˚
receivers, NEMA control panels, mechanical and electrical alternators,
magnetic starters, gauge glasses, and more.
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75
Pumps
NON-ELECTRIC CONDENSATE PUMPS
Why use a Pressure Motive Pump (PMP)?
The primary function of the non-electric PMPs is to return condensate back to the boiler. They are an excellent
alternative to standard electric pumps that are prone to seal failure when pumping hot condensate in excess of
195˚ F. They also significantly improve the performance and efficiency of heat exchangers by helping to drain
condensate from the heat exchanger during system stall conditions.
PUMPS
Information Required for Proper Selection and Sizing of Pressure Motive Pump (PMP) Systems
Although Pressure Motive Pumps can be supplied as stand-alone units, the vast majority of industrial condensate
transfer applications require a complete system of components to function both properly and efficiently. This section
is intended to familiarize the user with the information and components required to provide an efficient system.
Considerations for PMP System Sizing and Selection
1) Is a PMP required for the situation? Is there sufficient line pressure for adequate transfer of condensate,
or is a PMP required to overcome lift and/or condensate return line pressure?
2) Should you choose a Stand-alone pump or Pump with Receiver Tank (PMP System)? The vast majority of pump
applications require some type of receiver or reservoir upstream of the unit for several possible reasons:
• To allow proper operation of the PMP by providing adequate liquid head above
the PMP (Fill Height). Liquid fill head is required to ensure gravity drainage of
condensate so that the PMP tank may fill completely on each cycle.
• To enable the condensate to collect while the pump is in the discharge cycle
(i.e. not filling), thus preventing liquid backup into the equipment being drained.
• In an open loop system, a vented receiver must accommodate both high
pressure/temperature condensate as well as the flash steam generated from
that condensate. Sizing of both the receiver and vent connection are critical
to proper function of the system.
3) Application – OPEN LOOP (Vented Receiver) or CLOSED LOOP (Pressurized Reservoir)?
INLET FOR MULTIPLE
ATMOSPHERIC
12” SEAL
ON
OVERFLOW
CONDENSATE SOURCES
VENT
PUMP EXHAUST
FILLING
HEAD
12” Preferred
6” Min.
VENTED
RECEIVER
PRESSURE
MOTIVE
PUMP
MOTIVE STEAM OR
AIR SUPPLY
WD 600
TRAP
ALTERNATE
CONDENSATE
INLET
RETURN
LINE
PRESSURE
LIFT (ft.)
OPEN LOOP
This PMP System is intended for the
drainage of multiple condensate sources.
For these applications, a vented receiver
will be required for the equalization of the
various pressure sources. The flash steam
generated by the hot condensate in the
receiver tank can be used for supplementing other low pressure steam
systems or vented to atmosphere.
(Vented Receiver)
76
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Pumps
NON-ELECTRIC CONDENSATE PUMPS
CLOSED LOOP (Pressurized Reservoir)
STALL CONDITION WITH MODULATED STEAM FLOW
When a modulating valve is used to control product temperature in heat transfer equipment, the valve will open
PUMPS
and close as necessary to meet the variable demand of the system to maintain the product at constant temperature
(Figure 1). Therefore, when maximum heating is required, the supply valve will be fully open to satisfy the high steam
demand requirement. At this point, pressure is also being supplied at its highest level, which may be sufficient to
overcome total system back pressure.
As the product temperature is satisfied, demand decreases and the valve correspondingly begins to close reducing
pressure differential. If demand is satisfied, the valve modulates to its fully closed position. Inlet supply pressure will
eventually fall below system back pressure, resulting in system stall. This leads to poor heat transfer and water hammer as
condensate backs up in the heat transfer equipment. To prevent this situation, a pressure motive pump (PMP) and steam
trap is added to the system (
Figure 2).
Any condensate forming inside the heat transfer equipment will drain by
gravity into the pump tank. The condensate will accumulate in the pump tank until the float mechanism reaches
its trip point. The “tripping” of the mechanism opens the motive valve to allow high pressure steam into the tank to
drive the condensate from the tank to the condensate return line.
Figure 2
STEAM CONTROL
STEAM
HOT
OUTLET
COLD
INLET
VALVE
AIR
ENT
V
HEAT
EXCHANGER
RESERVOIR
FILLING HEAD
INLET
CHECK VALVE
VENT
PRESSURE
MOTIVE
VACUUM
BREAKER
STEAM
INLET
PUMP
Heat Exchanger System with PMP & Separate T
(Closed Loop System)
CONDENSATE
RETURN
STEAM
THERMODYNAMIC
DISC TRAP
F&T
TRAP
OUTLET
CHECK VALVE
STEAM
HOT
OUTLET
Figure 1
COLD
INLET
STEAM CONTROL
VALVE
AIR
VENT
HEAT EXCHANGER
VACUUM
BREAKER
F&T
TRAP
Heat Exchanger System
without PMP
CONDENSATE
RETURN LINE
-
4) Height or spatial limitations – Is the equipment to be drained low to the ground or are there other size limitations?
It is important that minimum fill head requirements are met to ensure proper operation of the PMP. In addition,
changes in fill head will affect capacity.
LIFT
rap
5) Standard Simplex/Duplex/Triplex/Quadraplex or Custom System – This is generally dictated by sizing requirements
and application parameters, but a cost-effective standard system should be selected when possible. Custom
fabricated systems are designed to meet a wide variety of specific application requirements. Note: The sizing of
the receiver and vent connection on standard systems must be specified per the application parameters.
6) Back pressure – For proper sizing and selection of a PMP system, the total back pressure of the system must be known.
The total back pressure generally consists of:
• The vertical height the condensate must be raised (Every 1 foot of vertical lift equals 0.433 PSI pressur
e.)
• Any line pressure in the condensate return piping
7) Motive Gas and Pressure – Is the gas (steam, air, other) appropriate for the application and is the available pressure
sufficient to provide the necessary flow against the total back pressure? (For closed loop systems, only steam is
appropriate as a motive.)
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The Watson McDaniel PMP Series of Pressure Motive Pumps
PUMPS
are designed to transfer hot condensate (as well as other liquids)
without the use of electrical energy. The primary application
for the PMP is pumping condensate from a process application
or condensate collection area back to the condensate return
system.
Hot Condensate The mechanical seals in standard electric
condensate return pumps begin to have difficulty when handling
condensate in excess of 195˚ F. Seal failure is virtually
guaranteed when condensate temperatures reach 203˚ F due to
flashing of the condensate acr
required to cool condensate in order to prevent seal failure prior
to pumping using electric pumps. PMPs do not have seals and
therefore will handle condensate well in excess of these
temperatures.
oss the seal face. It is therefore
TYPICAL CONFIGURATIONS
STAND ALONE UNITS:
All stand alone units are furnished with pump tank, check valves:
and internal pumping mechanism.
• PMPC • PMPF • PMPSS • PMPLS • PMPM • PMPBP
PUMPS WITH RECEIVER TANKS:
One or more stand alone pump units connected to an
appropriately sized receiver tank mounted on a common base.
Additional pumping units can be used for increased capacity or
pump redundancy in case of failure.
Simplex: One Pumping unit with check valves and receiver
tank, mounted on frame and skid base.
Duplex: Two Pumping units with check valves and receiver
tank, mounted on frame and skid base.
Triplex: Three Pumping units with check valves and receiver
tank, mounted on frame and skid base.
Quadraplex: Four Pumping units with check valves and
receiver tank, mounted on frame and skid base.
PUMP & STEAM TRAP COMBINATIONS:
Stand alone pump combined with Internally or Externally
configured Steam Trap.
• PMPT (Internal Steam Trap)
• WPT Series (External Steam Trap)
Several choices of pump body materials, types and
configurations are available to meet specific customer
applications:
Ductile Iron Tanks Ductile Iron is far superior to cast iron in
handling higher pressures and temperatures. Ductile iron is also
extremely corrosion resistant to condensate and water and
can last in excess of 50 years before tank replacement is required.
Our ductile iron tanks can be ASME coded on request.
Fabricated Carbon Steel Carbon steel has a higher
pressure and temperature rating than ductile iron. Certain industrial
facilities such as chemical and petrochemical refineries request
carbon steel only. Our carbon steel tanks are standard ASME
coded.
Fabricated Stainless Steel Stainless steel (304L) tanks are the
most corrosion resistant and can be used in extremely harsh
environments.
Low Profile Low profile tanks are often required when draining
condensate fr
ground which limits filling head. Low profile units are available in
both fabricated steel and cast iron.
om process equipment when positioned close to the
Sump Drainers Sump drainers are similar to the standard PMP
models except that they discharge the condensate vertically
upwards. This piping configuration allows them to easily fit
into below ground sump pits with limited space.
FEATURES
• Seal-less – The PMP contains no seals. The weak point in
conventional electric pumps is seal failure due to flashing
hot condensate across the seal face.
• Non-Electric
used in remote locations or NEMA 4,7 & 9 hazardous areas.
Can operate using steam, air, nitrogen or other pressurized
gases as the motive force.
• Ductile-Ir
which is far superior to Cast Iron for pressure and
temperature rating and safety. Can be ASME coded and
can last in excess of fifty years prior to replacement.
• Carbon Steel
carbon steel.
• Stainless Steel
applications in harsh environments.
– Since no electricity is required they can be
on – Pump tanks are standard in Ductile Iron
– Pump tanks available in ASME coded
– Pump tank options include 304L for
SUMP DRAINER:
Stand alone Sump Drainer with check valves is designed for
pumping water out of low lying areas or pits. Excellent solution
where there is no access to electricity.
• PMPSP
CUSTOM CONFIGURATIONS
Watson McDaniel’s fully-qualified fabrication facility is ASME
code certified. Our engineers can design and build complete
custom systems to meet all your requirements.
78
428 Jones Boulevard • Limerick Airport Business Center • Pottstown PA • 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
OPTIONS
• Pump cycle counter used for predicting maintenance intervals
as well as calculating the volume of condensate pumped.
• Insulation jackets are available to stop heat losses
through the pump body and provide personal protection.
• Sight glass for monitoring liquid level inside pump body.
• Customized systems – ASME code-certified fabrication facility
www.watsonmcdaniel.com
NON-ELECTRIC CONDENSATE PUMPS
PMP Series
Pressure Motive Pumps
STAND ALONE UNITS
All stand alone units are furnished with pump tank, check valves and internal pumping mechanism.
PUMPS
PMPC
The Model PMPC pressure motive
pump body & cover are manufactured
from ductile ir
stamp is available.
PMPSS
The Model PMPSS pressure motive
pump body & cover are manufactured
from 304L stainless steel
are designed to be used in harsh
corrosive environments and
receive the
PMPM
The Model PMPM pressure motive
pump has an
low profile
are required when draining condensate
from process equipment positioned
close to the ground which limits the
filling head of the pump.
DUCTILE IRON
on. ASME “UM” code
STAINLESS STEEL
. These tanks
ASME “UM” code stamp.
CAST IRON LOW PROFILE
extremely
. These low-profile tanks
PMPF
The Model PMPF pressure motive pump
is designed for high pr
Pump body & cover are manufactured from
carbon steel
code stamp.
CARBON STEEL HIGH-PRESSURE
essure applications.
and receive the ASME “UM”
PMPBP
The PMPBP is an
pressure motive pump for applications
requiring large transfer of condensate or
other liquids. The internal operating
mechanism functions identically to other
pumps in the PMP series. ASME “U” code
stamp is available.
PMPLS
The Model PMPLS pressure motive pumps are
low pr
draining condensate from process equipment
positioned close to the ground which limits the
filling head of the pump. Pump body & cover
are manufactured from carbon steel
the ASME “UM” code stamp.
CARBON STEEL HIGH-CAPACITY
extremely high-capacity
CARBON STEEL LOW PROFILE
ofile. These tanks are often required when
and receive
PUMP & TRAP COMBINATIONS
with Internal Steam Trap
PMPT
The Model PMPT low-profile
pressure motive pump comes
with an Internal Steam Trap.
It is an excellent choice for
drainage of various modulating
process equipment. The
internal steam trap allows
condensate discharge under
all operating conditions of
modulating equipment,
including vacuum.
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with External Steam Trap
WPT
The WPT Series ar
alone pump units with an
opriately sized
appr
Steam Trap preassembled at
the factory and mounted on a
common base plate, allowing
for easy installation. Available
in several sizes and capacities.
Used when load r
exceeds that of the PMPT.
e stand
nal
Exter
equirement
PUMPS WITH
RECEIVER TANKS
Watson McDaniel manufactures
PMPs with receiver tanks. Pumps
are available in Ductile Iron, Cast
Iron or Fabricated Steel. Receiver
tank manufactured from Carbon
Steel. Available in Simplex,
Duplex, Triplex and Quadraplex.
SUMP DRAINER
PMPSP
The Model PMPSP sump
drainer body & cover are
manufactured from Carbon
Steel. The Model PMPSP
Sump Drainer is designed
for pumping out and
draining pits.
1 Condensate flows from the receiver tank thru the inlet check valve and fills
the pump tank. During the filling cycle the float inside the tank rises.
RETURN LINE
PRESSURE
RETURN LINE
LIFT PRESSURE
IN PSI
(FEET X 0.433)
VENT
OUTLET
(closed)
Closed
MOTIVE
INLET
(open)
Open
INLET
CLOSED
2 When the pump tank has filled to the trip point, the mechanism triggers,
opening the motive gas inlet valve and simultaneously closing the vent valve.
This allows motive pressure to enter the pump body, which drives the condensate
thru the outlet check valve into the condensate return line. During the discharge
cycle, the liquid level and the float inside the pump tank drop.
OUTLET
CLOSED
OUTLET
OPEN
FLOW
CONDENSATE
80
VENT TO
ATMOSPHERE
VENTED
RECEIVER
FILLING HEAD
INLET
CHECK VALVE
PUMP
EXHAUST
VENT
PUMP
MOTIVE
GAS
INLET
PUMP MOTIVE
PRESSURE
DRIP TRAP
TO DRAIN
OR VENT
OUTLET
CHECK VALVE
RETURN LINE
PRESSURE
RETURN LINE
LIFT PRESSURE
IN PSI
(FEET X 0.433)
3 At the lower trip point, the mechanism triggers and the motive gas inlet valve to the
pump tank closes and simultaneously the vent valve opens. The fill and discharge
cycle then repeats itself.
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VENT
OUTLET
(open)
Open
MOTIVE
INLET
(closed)
Closed
FLOW
INLET
OPEN
• 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
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OUTLET
CLOSED
NON-ELECTRIC CONDENSATE PUMPS
PMP Series
Pressure Motive Pump Internal Mechanism
PUMPS
COVER
Patented
SNAP-ASSURE™
Feature
Guaranteed to
extend pump life
even in the most
demanding
applications.
PINS AND
WEAR POINTS
Pivot pins and wear
points are made
from heat-treated
stainless steel with a
heavy layer of hard
chrome plating.
1/2” NPT
INLET
1” NPT
OUTLET
VENT
INLET AND VENT VALVES
Made from heat-treated
17-4 stainless steel; adds
durability for extended life.
INCONEL-X-750
DUAL COMPRESSION SPRINGS
Designed to minimize
stresses and last indefinitely.
ALL STAINLESS
STEEL
INTERNALS
SUPPORT
BRACKET
INTERNAL MECHANISM FEATURES
• Equipped with our Patented “Snap-Assure” feature, found only
on Watson McDaniel’s mechanisms. “Snap-Assure” extends the
useful life of the pump by assuring that the internal toggle
action triggers at every fill and discharge cycle
• All Stainless Steel components eliminate corrosion and rusting
• Hard chrome-plated pivot pins and wear points substantially
reduce the rate of wear on critical components
• 17-4 heat-treated stainless steel inlet and vent valve (Hardened
seats have pr
• Dual compression springs made from Inconel-X-750 minimize
stress and corrosion and are designed to last indefinitely
• Precision manufactured mechanisms never require
field adjustments
• Watson McDaniel “Snap-Assure” mechanisms can be purchased
separately and will fit other manufacturers’ pump tanks
oven themselves to last years longer in service)
428 Jones Boulevard • Limerick Airport Business Center • Pottstown PA • 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
The PMPC pressure motive pump body & cover are
manufactured from ductile ir
available
must be moved to higher elevation, higher pressure
or extended distances.
. This pump is typically used when liquids
on. ASME “UM” code stamp is
FEATURES
Equipped with our
•
which extends the useful life of the pump
Mechanism incorporates heat-treated stainless steel
•
wear items
All stainless steel internals for ultimate corrosion resistance
•
Dual compression springs made from Inconel-X-750 for
•
high-temperature corrosive service
Operates using steam, air, nitrogen or other pressurized
•
gases as the motive force
Non-Electric – can be used in remote locations or
•
NEMA 4, 7, 9 & hazardous areas
Patented “Snap-Assur
e” Mechanism
SAMPLE SPECIFICATION
The non-electric pressure powered pump shall be capable of operating
with a maximum motive pressure of 200 PSIG provided by steam, air
or other gas supply. The pump body shall be cast ASTM A-395 Ductile
Iron capable of an ASME “UM” code stamp if requested. The pump
mechanism shall be float operated with a patented “Snap-Assure”
feature constructed of all stainless steel materials with all load bearing
points hardened for extended service life. The mechanism shall feature
two Inconel springs used in compression with motive & vent valves
hardened to 40c Rockwell.
Max. Operating Temperature
Max. Allowable Pressure
PMA
200 PSIG
388ºF
250 PSIG @ 650˚F
FABRICATED STEEL TANK
PMPF
Pressure Motive Pump
PUMPS
TYPICAL APPLICATIONS
The PMPF pressure motive pump body & cover are manufactured
from carbon steel
allowance and receive the ASME “UM” code stamp. This pump
is typically used when liquids must be moved to higher elevation,
higher pressure or extended distances.
. These tanks are fabricated with 1/8” corrosion
FEATURES
Equipped with our Patented “Snap-Assure” Mechanism
•
•
•
•
•
•
extends the useful life of the pump
which
Mechanism incorporates heat-treated stainless steel
wear items
All stainless steel inter
Dual compression springs made from Inconel-X-750 for
high-temperature corrosive service
Operates using steam, air, nitrogen or other pressurized
gases as the motive force
Non-Electric – can be used in remote locations or
NEMA 4, 7, 9 & hazardous areas
nals for ultimate corrosion resistance
SAMPLE SPECIFICATION
The non-electric pressure powered pump shall be capable of operating
with a maximum motive pressure of 200 PSIG provided by steam, air or
other gas supply. The pump body shall be fabricated carbon steel and
certified with the ASME “UM” code stamp. The pump mechanism shall
be float operated with a patented “Snap-Assure” feature constructed of
all stainless steel materials with all load bearing points hardened for
extended service life. The mechanism shall feature two Inconel springs
used in compression with motive & vent valves hardened to
40c Rockwell.
The PMPSS pressure motive pump body & cover are
manufactured from 304L Stainless Steel
the ASME “UM” code stamp. This pump is designed to be
used in harsh and corrosive environments.
. These pumps receive
FEATURES
Equipped with our Patented “Snap-Assure” Mechanism
•
which extends the useful life of the pump
Mechanism incorporates heat-treated stainless steel
•
wear items
All stainless steel internals for ultimate corrosion resistance
•
Dual compression springs made from Inconel-X-750 for
•
high-temperature corrosive service
Operates using steam, air, nitrogen or other pressurized
•
gases as the motive force
Non-Electric – can be used in remote locations or
•
NEMA 4, 7, 9 & hazardous areas
SAMPLE SPECIFICATION
The non-electric pressure powered pump shall be capable of operating
with a maximum motive pressure of 150 PSIG provided by steam, air or
other gas supply. The pump body shall be 304L Stainless Steel and
certified with the ASME “UM” code stamp. The pump mechanism shall
be float operated with a patented “Snap-Assure” feature constr
all stainless steel materials with all load bearing points hardened for
extended service life. The mechanism shall feature two Inconel springs
used in compression with motive & vent valves hardened to
40c Rockwell.
Max. Operating Temperature
Max. Allowable Pressure
PMA
Note: Optional 200 PSIG PMA/PMO. Consult Factory.
150 PSIG
366ºF
150 PSIG @ 650˚F
PMPLS
Pressure Motive Pump
PUMPS
TYPICAL APPLICATIONS
The PMPLS pressure motive pump is a lower profile than the
standard PMPF model and is sometimes required when draining
condensate from process equipment that is positioned close to the
ground which limits the filling head of the pump. Pump & body
cover are manufactured from carbon steel and receive the
ASME “UM” code stamp.
FEATURES
Equipped with our Patented “Snap-Assure” Mechanism
•
which extends the useful life of the pump
Mechanism incorporates
•
wear items
All stainless steel internals for ultimate corrosion resistance
•
Dual compression springs made from Inconel-X-750 for
•
high-temperature corrosive service
Operates using steam, air, nitrogen or other pressurized
•
gases as the motive force
Non-Electric – can be used in remote locations or
•
NEMA 4, 7, 9 & hazardous areas
eated stainless steel
heat-tr
SAMPLE SPECIFICATION
The non-electric pressur
with a maximum motive pressure of 150 PSIG provided by steam, air or
other gas supply. The pump body shall be fabricated carbon steel and
certified with the ASME “UM” code stamp. The pump mechanism shall
be float operated with a patented “Snap-Assure” feature constructed of
all stainless steel materials with all load bearing points har
extended service life. The mechanism shall feature two Inconel springs
used in compression with motive & vent valves hardened to
40c Rockwell.
The capacity of the PMPM is based on the inlet steam pressure,
the system back pressure, and the amount of filling head
available. The trap used in a pump-trap combination must
be sized to handle the instantaneous discharge of the pump.
Choose a F&T trap that will pass the condensate load at a 1/4
PSI differential pressure. The PMO of the steam trap must be
higher than the motive inlet steam pressure. Consult factory for
proper choice of steam trap.
86
428 Jones Boulevard • Limerick Airport Business Center • Pottstown PA • 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
Max. Operating Temperature
Max. Allowable Pressure
PMA
150 PSIG
366ºF
150 PSIG @ 470˚F
TYPICAL APPLICATIONS
The PMPBP is an
pump for applications requiring large transfer of condensate or
other liquids. The internal operating mechanism functions
identically to other pumps in the PMP series. ASME “U” code
stamp is available.
extremely high-capacity
pressure motive
FEATURES
All stainless steel internals for ultimate corrosion resistance
•
Operates using steam, air, nitrogen or other pressurized
The PMPSP Sump Drainer uses the identical internal mechanism as the standard
PMP models. The piping configuration is such that the liquid is discharged vertically
upwards as opposed to horizontally out the side. This allows the unit to be easily
positioned inside of a sump area. Condensate or water from the sump enters the
tank through a stainless steel low resistance check valve.
FEATURES
Equipped with our Patented “Snap-Assure” Mechanism which
•
extends the useful life of the pump
Mechanism incorporates heat-treated stainless steel wear items
•
All stainless steel internals for ultimate corrosion resistance
•
Dual compression springs made from Inconel-X-750 for
•
high-temperature corrosive service
Operates using steam, air, nitrogen or other pressurized gases as the
•
motive force
Non-Electric – can be used in remote locations or NEMA 4, 7, 9
•
& hazardous areas
Built-in strainer screen
•
INLET
Stainless Steel
Check Valve
88
428 Jones Boulevard • Limerick Airport Business Center • Pottstown PA • 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
A Pump-Trap Combination is used when draining condensate from a single piece of heat
transfer equipment whose steam flow is being controlled with a modulating type valve. When
a modulating valve controls the flow of steam to a heat exchanger, a stall condition can develop.
Stall occurs when the modulating valve closes and steam pressure downstream of the valve
is unable to push the condensate into the return line and it backs up into the heat exchanger.
A Pump-Trap combination will eliminate this problem.
Pump-Traps with either Internal or External Steam Trap designs are available
to suit individual application requirements.
and/or materials of its
Pump with Internal Steam Trap
PMPT
The Model PMPT low-profile pressure motive pump
has an internal Steam Trap for applications requiring
compact design due to spatial constraints. It is an
excellent choice for drainage of various modulating
process equipment.
The Pump-Trap Combination allows condensate discharge under all operating conditions
of modulating equipment, including vacuum.
Pump with External
Steam Trap
WPT
The WPT Series are stand-alone pump units with an
appropriately sized Steam Trap preassembled at the factory
and mounted on a common base plate, allowing for simple
installation. Pump-trap combos with an external trap are
suitable when capacity requirements exceed internal steam
trap designs. Available in several sizes and capacities.
92
428 Jones Boulevard • Limerick Airport Business Center • Pottstown PA • 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
www.watsonmcdaniel.com
NON-ELECTRIC CONDENSATE PUMPS
Problem:
DESCRIPTION:
PMPT &WPT
Pressure Motive Pump & Trap Combinations
PUMPS
Stalled Heat Exchanger
STALL CONDITION WITH MODULATED
STEAM FLOW
When a modulating valve is used to control product
temperature in heat transfer equipment, the valve will
TEAM
S
STEAM CONTROL
VALVE
AIR
VENT
open and close as necessary to meet the variable
demand of the system to maintain the product at
constant temperature. Therefore, when maximum
heating is required, the supply valve will be fully
open to satisfy the high steam demand requirement.
HOT
OUTLET
HEAT EXCHANGER
At this point, pressure is also being supplied at its
highest level, which may be sufficient to overcome
total system back pressure.
COLD
INLET
As the product temperature is satisfied, demand
decreases and the valve correspondingly begins
to close, reducing pressure differential. If demand
is satisfied, the valve modulates to its fully closed
position. Inlet supply pressure will eventually fall
below system back pressure, resulting in system
stall. This leads to poor heat transfer and water
Heat Exchanger System
without PMP
hammer as condensate backs up in the heat
transfer equipment.
Solution: Use PMP & Steam Trap Combination
DESCRIPTION:
USE A PRESSURE MOTIVE PUMP
AND STEAM TRAP COMBINATION
(Available in INTERNAL and EXTERNAL
Steam Trap designs)
When the supply valve is fully open and
inlet pressure exceeds back pressure,
condensate forming in the heat transfer
equipment will be pushed through the pump
and steam trap into the condensate return
line. As the supply valve begins to close
and the back pressure exceeds inlet
pressure, any condensate forming inside the
heat transfer equipment will drain by gravity
into the pump tank. The condensate will
accumulate in the pump tank until the float
mechanism reaches its trip point. The
“tripping” of the mechanism opens the
motive valve to allow high pressure steam
into the tank to drive the condensate from
the tank to the condensate return line.
Note: A larger steam trap than normally
required to drain the heat transfer equipment
must be used to handle the high instantaneous discharge rate of the pump. See
additional information in this catalog for
sizing guidelines.
STEAM
HOT
OUTLET
COLD
INLET
Heat Exchanger System with PMP & Internal Trap (PMPT)
STEAM CONTROL
VALVE
HEAT
EXCHANGER
RESERVOIR
FILLING HEAD
INLET
CHECK VALVE
AIR
VENT
VENT
PMPT
PRESSURE
MOTIVE
PUMP/TRAP
COMBINATION
(Closed Loop System)
VACUUM
BREAKER
VACUUM
BREAKER
STEAM
INLET
CONDENSATE
RETURN LINE
F&T
TRAP
STEAM
THERMODYNAMIC
DISC TRAP
OUTLET
CHECK VALVE
CONDENSATE
RETURN
LIFT
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The Model PMPT low-profile pressure motive pump has an internal
Steam Trap for applications requiring compact design due to spatial
constraints. It is an excellent choice for drainage of various
modulating process equipment.
The PMPT allows condensate discharge under all operating
conditions of modulating equipment, including vacuum.
FEATURES
Compact, low-profile design allows for drainage of
•
equipment positioned close to the floor
The PMPT provides provides condensate drainage for
•
modulating equipment, preventing inefficient and dangerous
system stall
Equipped with our proven, Patented “Snap-Assure”
•
mechanism which extends the useful life of the pump
Internal mechanism can be removed from the top of the
•
pump while pump remains piped in line
Mechanism incorporates heat-treated stainless steel
•
wear items
Dual compression springs made from Inconel-X-750 for
WPT Series Pump-Trap Combinations simplify
Selection & Installation of Pressure Motive Pumps
PUMPS
• 5 size ranges available
• Up to 13,000 lbs/hr of condensate load
TYPICAL APPLICATIONS
The Watson McDaniel WPT Pump-Trap Combinations are excellent for draining
heat exchangers or other equipment that is being fed by a temperature regulator
or a temperature control valve. In these applications, the steam pressure in the
heat exchanger may not be sufficient to overcome the back pressure in the
condensate return line. When this condition occurs, the pressure powered pump
takes over and uses high pr
condensate through the trap. When sufficient pressure does exist, the system
functions like a standard steam trap.
PUMP-TRAP FEATURES
Pump and Steam Trap are pre-mounted together on a single base
•
for easy installation
Engineering and selection is simplified
•
NOTE: Reservoir - The majority of Pump-Trap Combination applications require a
reservoir above the pump to accommodate any condensate back-up during
the discharge cycle of the pump. Consult Reservoir Sizing Guidelines or
contact factory for additional information.
essure steam supplied to the pump to discharge the
WPT1 - 1” x 1”
25”
1” FNPT OUTLET
11/2” FTE-200 TRAP
4”
(PMPM with 1
1” FNPT INLET
PMPM
28”
1
/2” FTE-200)
VENT
1/2” FNPT
MOTIVE
1/2” FNPT
14
1
/8”
CAPACITIES –
MotiveTotal BackWPT1WPT2WPT3WPT4WPT5
PressurePressure1” x 1”11/4” x 11/4”1
(PSIG)(PSIG)6” Head6” Head12” Head12” Head12” Head
Four standard condensate receiver sizes are available for our Pressure
Motive Pump Systems: 21, 48, 75 and 116 gallons. Custom Receiver
PUMPS
fabrication is available with our ASME certified fabrication facility.
Cycle
Counter
Gauge Glass
Pump Tanks are available with gauge glass
to show condensate level inside the tank.
(bronze or stainless steel retainer)
Cycle Counter
•The cycle counter option allows you to
calculate and measure condensate flow
through the pump on vented systems. This also
gives an indication when maintenance and
repairs to your mechanism may be required.
Gauge
• Proper selection of the appropriate cycle
Glass
counter is required: consult factory.
• The low-differential pressure cycle counter must
be selected for applications where total pump
back pressure is below 15 PSIG.
• Special cycle counter required when used
on Closed Loop Systems.
Pre-Piped PRV & Drip Leg
A fully-assembled Pre-piped PRV, Drip Leg, or PRV and
Drip Leg Assembly guarantees proper installation of
your PMP System. It assures that your skid package
performs to optimum levels.
“T-Bone”
Connection
Inlet
Check
Valve
Product DescriptionModel Code
GAUGE GLASS:Standard Bronze
for PMPC, PMPF, PMPLS, 21 Gallon ReceiverGauge Glass 1
for PMPTGauge Glass PMPT
for PMPM Mini Pump (extremely low profile)Gauge Glass PMPM
for 48 Gallon ReceiverGauge Glass 1
for 75 Gallon ReceiverGauge Glass 1
for 116 Gallon ReceiverGauge Glass 1
Stainless Steel
for PMPSSGauge Glass SS
Following Options are available for gauge glasses. Contact factory.
Auto Drain (self-drain) Stainless Steel ArmoredGauge Glass 1A
Reflex Gauge for PMPC, PMPF, PMPLS, 21 Gallon Receiver
Vertical
Outlet
Check
Valve
Gauge Glass - 1HP
Discharge
Pump
Vertical Discharge
Pump with “T-Bone”
connection allows inlet
and outlet condensate
hook-ups to be made
above the pump. This
is an advantage when
space is limited around
the base of the pump
due to equipment or
piping obstructions.
CYCLE COUNTER:
Digital Cycle Counter (fits all PMPs)Specify open or closed system
Low Pressure Cycle Counter (fits all PMPs)
ASME Code Stamp:for PMPC, PMPT & PMPBP Pump Tank
(Standard on 21, 48, 75, 116 Gallon Receivers and PMPF, PMPLS, PMPSS pump tanks)
INSULATION JACKET:
for PMPC Ductile Iron PumpINSUL-CRV-PMPC
for PMPF Fabricated Steel PumpINSUL-CRV-PMPF
for PMPLS Low Profile PumpINSUL-CRV-PMPLS
for PMPBP High Capacity PumpINSUL-CRV-PMPBP
for PMPT Pump-TrapINSUL-CRV-PMPT
for PMPM Mini Pump (extremely low profile)INSUL-CRV-PMPM
for 21 Gallon ReceiverINSUL-CRV-21
for 48 Gallon ReceiverINSUL-CRV-48
for 75 Gallon ReceiverINSUL-CRV-75
for 116 Gallon ReceiverINSUL-CRV-116
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98
(Contact Factory)
www.watsonmcdaniel.com
NON-ELECTRIC CONDENSATE PUMPS
Insulation Jacket
Insulation Jackets
conserve energy by
reducing heat loss. They
also improve safety by
protecting personnel from
hot surfaces. Jackets
have velcro closures
for easy installation or
removal. Fits tightly
around pump tanks
and receivers.
Accessories & Options
Pressure Motive Pumps
PUMPS
Patented “Snap-Assure” Feature
• Patented “Snap-Assure” feature is found only
on Watson McDaniel’s pump mechanisms.
“Snap-Assure” extends the useful life of the pump
by assuring the internal mechanism toggles at every
fill and discharge.
• “Snap-Assure” is supplied standard in Models PMPC,
PMPF, PMPT, PMPLS, PMPSS & PMPSP.
• “Snap-Assure” mechanisms will also fit other
manufacturers’ pump tanks.
• Mechanisms are simple and easy to replace, and are a
cost-effective way to make your pump as good as new.
Snap-Assure Patent No. 6572340
Product Description
PRE-PIPED ACCESSORIES:
Pre-piped Pressure Regulating Valve (PRV) for motive steam or air PRV1
Pre-piped Drip Leg Station with Steam TrapPRV2
Pre-piped Drip Leg Station with Steam Trap and PRVPRV3
Pre-piped Exhaust LinePRV4
MECHANISMS:New Mechanism Assembly with Cover
for PMPF900-03
for PMPC, PMPLS910-03
for PMPBP900-02
for PMPT921-03
for PMPM (cover not required)911-03
REBUILT MECHANISMS: *
for PMPF900-03R
for PMPC, PMPLS910-03R
for PMPT921-03R
CHECK VALVES:
Stainless Steel: 1/2” - 3” NPT
* Note for Rebuilt Mechanisms:
The exchange program is for mechanisms with two years of service or less. The old mechanism must be returned along with the
order for the rebuilt mechanism. Orders without old mechanisms will be invoiced at the new mechanism price.
Model Code
See WSSCV Page
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NOTE: When the filling head differs from the standard filling height, the capacity
of the pressure power pumps are either increased or decreased. For example,
a pump with a 3” inlet that has a filling head of 36” as opposed to a standard
filling head of 12”, will have a capacity increase of 20%. Multiply the value
found in the Capacity Table above by 1.2.
6”12”18”24”36”48”60”
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100
Condensate (lbs/hr) Using steam as a motive pressure
PMPC, PMPF, PMPSS*
11/2”
X 11/2”
2” X 1”2” X 11/2”2” X 2”3” x 2”3” x 2”3” x 2”3” x 2”4” x 4”
Capacity Correction Factors for Gas as Motive Pressure
determined by the Model and the size of the inlet
and outlet check valves. The larger the check valves
used, the more capacity the pump can handle.
For example: The 3” x 2” pump has a 3” inlet check
valve and a 2” outlet check valve.
STAND-ALONE PUMPS are furnished with pump tank,
check valves and internal pumping mechanism.
PUMPS WITH RECEIVER TANKS include the standalone pump(s), check valves, and receiver tank
mounted together on a frame. These are available in
Simplex, Duplex, Triplex and Quadraplex systems.
When sizing and selecting a Pressure Motive Pump,
five system conditions are required:
(See Diagram on following page)
1 Condensate Load
2 Condensate Pressure
3 Motive Steam, Air or other Gas Pressure available
for operating the pump
4 Available Filling Head between the bottom of the
receiver tank and the top of the pump tank
5 Total System Back Pressure (BP)
a) Condensate Return Line Pressure (5A)
b) Vertical Height condensate must be lifted (5B)
Open Loop with Vented Receiver
(When draining condensate from multiple sources)
For PMP Sizing:
Consult PMP Sizing Capacity Chart using 100 PSIG
inlet pressure and 40 PSIG back pressure. A 2" x 2" pump
has a capacity of 8,500 lbs/hr and is an appropriate
selection. Pump choices are models PMPC, PMPF
and PMPSS.
For Receiver and Vent Connection Sizing:
Refer to the Vented Receiver Sizing Chart for guidelines
on how to calculate the flash steam generated and use
this value to size the receiver and vent connection.
Closed Loop with Pressurized Reservoir
(When draining condensate from a single piece of
heat transfer equipment)
For PMP and Trap Sizing:
Reference PMPT and WPT Pump-Trap Combination
Capacity Charts for an estimation of the unit required.
Contact factory for more accurate sizing.
For Reservoir Pipe Sizing
Refer to the Reservoir Pipe Length Chart for guidelines
on determining the appropriate diameter and length
of pipe required for condensate back-up.
HOW TO ORDER
SAMPLE SYSTEM CONDITIONS
1 Condensate Load8,000 lbs/hr
2 Condensate Pressure50 PSIG
3 Motive Steam PressureSteam @ 100 PSIG
4 Filling Head12"
5 Total Back Pressure = a + b
a) Line Pressure30 PSIG
b) Vertical Lift23 ft.
(convert to PSIG)
Calculation of Total Back Pressure:
To find the pressure required to lift condensate in PSIG,
multiply the lift in feet by 0.433.
Pressure required to lift Condensate10 PSIG
(0.433 x 23 ft.)
Pressure in Return Pipe+ 30 PSIG
Total Back Pressure= 40 PSIG
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102
SPECIFY:EXAMPLE:
1) Model or PumpsPMPC
2) Size of Pump(s)2” x 2”
3) Stand-alone Pump or Simplex or Duplex
Pump with Receiver Tank
(Note: Size of Receiver Tank must be specified when
ordering Pump with Receiver Tank)
4) OptionsGauge glass
5) When ordering a Customized
Skid System, please confirm
and specify Receiver size.
www.watsonmcdaniel.com
NON-ELECTRIC CONDENSATE PUMPS
CONDENSATE LOAD:
1
CAN BE FROM SINGLE OR MULTIPLE
CONDENSATE SOURCES
CONDENSATE PRESSURE
2
OPEN LOOP
CLOSED LOOP
- VENTED RECEIVER
- PRESSURIZED
RECEIVER TANK
FILLING HEAD
4
(12” PREFERRED)
CONDENSATE
INLET
ATMOSPHERIC
VENT SIZE
(OPEN LOOP ONLY)
Sizing & Selection
Pressure Motive Pumps
PUMPS
PMP Sizing & Selection
TOTAL BACK PRESSURE
5A
CONDENSATE RETURN
LINE PRESSURE
PSIG
PUMP
EXHAUST
MOTIVE STEAM
OR GAS
PRESSURE
AVAILABLE
3
5B
LIFT
HEIGHT
FT. X 0.433 =
PSIG
PMP:
SIMPLEX
OR
MULTIPLEX
STEAM TRAP
(REQUIRED FOR CLOSED LOOP
PMP SYSTEM ONLY)
Simplex or Multiplex PMP System
5
= TOTAL BP
5B
5A
5
= + = TOTAL BP
PSIG
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www.watsonmcdaniel.com
103
NON-ELECTRIC CONDENSATE PUMPS
Sizing & Selection
Pressure Motive Pumps
Closed Loop System (Pressurized Reservoir)
RESERVOIR SIZING
PUMPS
When sizing Pressure Motive Pumps for closed loop return
systems, a condensate reservoir should be installed on the
inlet side of the pump and below the equipment to be drained.
This will enable the condensate to collect while the pump is
in the discharge cycle, thus preventing liquid backup into the
equipment. The Reservoir Sizing Table (at right) gives the
minimum pipe size & length to produce the required reservoir
volume to accommodate the condensate load.
How to select: Determine the total condensate load to be
pumped. Find that load value or greater in the table and
move right to read the pipe lengths in feet with the diameters
indicated above.
Customized reservoirs can be designed to accommodate
specific space and dimensional requirements. It is critical for
these designs to have adequate vapor space for condensate to
collect. When the volume required is known, from the table at
right, optional pipe diameters and lengths can be selected to
provide the same or greater volume. This table will allow you
to convert required volumes to customized sizes needed.
Watson McDaniel can furnish customized Pressure Motive
Pump Packages to fit your needs.
and/or piping to allow for the installation of the
Reservoir and PMP with the Preferred Filling Head
of 12” as illustrated?
To size the PMP and Trap combination, see PMPT
or WPT Capacity charts for general reference.
(For additional information on the effect of the
steam trap in a closed loop application, refer to
expanded information later in this section. For more
accurate sizing of Pump-Trap systems to account
for system stall conditions, consult factory.)
To size the Reservoir, see Reservoir
Pipe Length chart.
PSIG
104
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NON-ELECTRIC CONDENSATE PUMPS
Sizing & Selection
Open Loop System (Vented Receiver)
RECEIVER & VENT SIZING
When sizing a Pressure Motive Pump for an
Open-Loop atmospheric return system, the amount
of flash steam to be vented from the receiver must be
calculated. Vent sizing is critical to maintain 0 PSIG
in the receiver tank to allow free drainage of low
pressure systems. Undersized vents will cause
gradual pressure increase in the receiver. This impedes
drainage from the condensate source, and can
cause waterlogging of the system.
Usually the condensate load to be pumped comes
from multiple sources. For each source determine
the pressure and load. Then go into the Percent Flash Steam table with
the condensate pressure and move right until under the appropriate flash
tank pressure to read the percentage of condensate that will flash into
steam. Take the source load and multiply it by the decimal value of the
percentage to calculate the amount (lbs/hrs) of flash steam. Repeat this for
all condensate sources. Enter the Vented Receiver Sizing table with the
total flash steam load to determine the correct sizes for receiver and vent.
PERCENT (%) FLASH STEAM
Produced when condensate is discharged to atmosphere or into a
flash tank controlled at various pressures
Is there enough clearance under the
equipment and/or piping to allow for the
installation of the Receiver and PMP with
the Preferred Filling Head of 12” as illustrated?
To size the PMP, see Pump Capacity chart.
To size the Receiver and Vent connection,
see Vented Receiver Sizing chart.
105
NON-ELECTRIC CONDENSATE PUMPS
Sizing & Selection
Pressure Motive Pumps
Problem: Stalled Heat Exchanger
DESCRIPTION:
PUMPS
STALL CONDITION WITH MODULATED
STEAM FLOW
When a modulating valve is used to control
product temperature in heat transfer equipment,
the valve will open and close as necessary to
meet the variable demand of the system to
maintain the product at constant temperature.
Therefore, when maximum heating is required,
the supply valve will be fully open to satisfy the
high steam demand requirement. At this point,
pressure is also being supplied at its highest
level, which may be sufficient to overcome
total system back pressure.
As the product temperature is satisfied, demand
decreases and the valve correspondingly begins
to close, reducing pressure differential. If demand
is satisfied, the valve modulates to its fully closed
position. Inlet supply pressure will eventually fall
below system back pressure, resulting in system
stall. This leads to poor heat transfer and water
hammer as condensate backs up in the heat
transfer equipment.
USE A PRESSURE MOTIVE PUMP
AND STEAM TRAP COMBINATION
(Available in INTERNAL and EXTERNAL
Steam Trap designs)
When the supply valve is fully open
and inlet pressure exceeds back pressure,
condensate forming in the heat transfer
equipment will be pushed through the pump
and steam trap into the condensate return
line. As the supply valve begins to close
and the back pressure exceeds inlet
pressure, any condensate forming inside
the heat transfer equipment will drain by
gravity into the pump tank. The condensate
will accumulate in the pump tank until the
float mechanism reaches its trip point. The
“tripping” of the mechanism opens the
motive valve to allow high pressure steam
into the tank to drive the condensate from
the tank to the condensate return line.
Note: A larger steam trap than normally
required to drain the heat transfer equipment
must be used to handle the high instantaneous discharge rate of the pump. See
additional information in this catalog for
sizing guidelines.
STEAM
HOT
OUTLET
COLD
INLET
Heat Exchanger System with PMP & Internal Trap (PMPT)
STEAM CONTROL
VALVE
HEAT
EXCHANGER
RESERVOIR
FILLING HEAD
INLET
CHECK VALVE
AIR
VENT
VENT
PMPT
PRESSURE
MOTIVE
PUMP/TRAP
COMBINATION
(Closed Loop System)
VACUUM
BREAKER
STEAM
INLET
STEAM
THERMODYNAMIC
DISC TRAP
OUTLET
CHECK VALVE
CONDENSATE
RETURN
LIFT
106
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www.watsonmcdaniel.com
NON-ELECTRIC CONDENSATE PUMPS
Sizing & Selection
Pressure Motive Pumps
CLOSED LOOP SYSTEMS –
SIZING CONSIDERATIONS for PUMP-TRAP COMBINATION
What is Stall?
PUMPS
STALL is the condition of a modulating system where inlet pressure can no longer overcome back pressure,
Although Pressure Motive Pumps can be supplied as stand-alone units, the vast majority of industrial condensate
transfer applications require a complete system of components to function both properly and efficiently. This section
is intended to familiarize the user with the information and components required to provide an efficient system:
The Solution to Stall
Install a Watson McDaniel Pump and Steam Trap Combination
The PMPT Pump with Internal Steam Trap should be considered for compactness, while the WPT Series Pump-Trap
Combination with External Steam Trap should be considered when capacities exceed the capability of the PMPT.
Why is a Steam Trap necessary after the PMP in a Closed Loop system?
Because this type of system operates with a modulating supply valve as described above, the pressure may, at times,
both exceed or fall below system back pressure. The pump is only required during stall loads. Therefore, a steam trap is still
required to prevent steam from discharging into the return line at times when the supply pressure exceeds the back pressure.
When properly sized and installed, these two components will automatically work in conjunction with each other requiring no
manual operation.
It is important to note that sizing the steam trap in a pump-external trap* combination application differs from sizing a
steam trap alone. Please refer to additional information below.
* Although the steam trap is internal in the PMPT Series, it is still appropriate to follow the guidelines below for sizing confirmation.
Sizing of a Pump-Trap Combination for a Closed Loop System
Although the PMP and Steam Trap operate in conjunction with each other, each component must be considered individually,
as there are specific considerations for closed loop systems. See below for detailed explanation and appropriate guidelines
for sizing of both the PMP and Trap components of the Pump-Trap Combination:
preventing condensate drainage and resulting in poor heat transfer and waterhammer.
– available in both Internal and External Steam Trap designs.
Proper Sizing of the PMP in a Pump-Trap Application
When required for drainage of heat transfer equipment supplied by a modulating control valve, the PMP need only be sized for
the stall load, which is often considerably less than equipment design load leading to a smaller PMP being required. The point
at which stall occurs can be calculated using either Stall Charts or appropriate formulas as shown on the following pages.
Proper Sizing of the Steam Trap in a Pump-Trap Application
In such an application, the steam trap must be sized not only to handle the full design load, but also sized to handle the high
instantaneous flow rates fr
steady-state load of the pump! Therefore, it is appropriate to size the steam trap for both sets of conditions using the
following guidelines:
• Steam Trap sizing based on
Full Design Load X appropriate Safety Load Factor = Total Load for Steam Trap Sizing
• Steam Trap sizing based on Instantaneous Discharge of the PMP – at stall conditions:
Stall Load (as determined) at 1/4 PSI differential for Steam Trap Sizing
om the discharge of the pump at stall conditions – which can be well in excess of 3 times the
Full Design Load of the Heat Transfer Equipment:
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107
NON-ELECTRIC CONDENSATE PUMPS
Watson McDaniel reserves the
right to change the designs
Sizing & Selection
Pressure Motive Pumps
Predicting Stall
Stall can be predicted with relative accuracy by either plotting values on a Stall Chart or by calculation using appropriate
formulas. These methods are then used to determine the percentage of heat load at stall. Examples of each method are
PUMPS
offered so the user may choose the method with which they are most comfortable.
The example below is for a typical heat transfer application**, such as a heat exchanger where steam may be used to
heat a constant flow of water at a fixed temperature. The parameters of such an application can be summarized as:
• The flow of the fluid to be heated is constant
• The desired outlet temperature of the heated fluid is to remain constant
• The steam for heating is to be supplied with a modulating valve (i.e. varying inlet pressure)
** Applications with alternate parameters will require different equations and guidelines for prediction of stall conditions.
Consult factory for other such applications.
Example:
Consider a heat exchanger supplied with 40 PSIG steam through a modulating valve that is designed to heat a
constant water flow of 145 GPM from 60 ˚F to 140 ˚F. Condensate will need to be lifted 23 ft. into a return
line that has approximately 5 PSIG back pressure.
Before the charts or formulas can be consulted, some additional conversions are first required:
1) The Saturated Temperature of the incoming steam: In this example, consult the Saturated Steam Table
(included in the Engineering Section of this catalog) to determine the Saturated Temperature
of 40 PSIG steam is 287 ˚F.
2) The equivalent Saturated Temperature of the total BACK PRESSURE: The total back pressure is equal
to the lift height equivalent pressure, plus any pressure that may exist in the return line.
• 23 ft. Lift Height x 0.433 = 10 PSIG
• Return Line Pressure = 5 PSIG
Therefore, the total BACK PRESSURE in this example is 15 PSIG. Consulting the Saturated Steam Table,
the saturated temperature of 15 PSIG steam is 250 ˚F.
The parameters required for determining stall can now be summarized as follows:
• Inlet Steam Pressure at Full (100%) Load = 40 PSIG (P
• Inlet Steam Temperature at Full (100%) Load = 287
• Outlet Temperature of Heated Fluid = 140 ˚F (T
• Back Pressure (lift height + line pressure) = 15 PSIG (P
• Back Pr
essure equivalent saturated steam temperature = 250 ˚F (T
Mathematical Solution
% Heat Load at Stall = Tb – T2 x 100%
S – T2
T
=250 – 140 x 100%
287 – 140
x 100%
147
Graphical Solution (see Figur
1) On the Left Vertical Axis, plot the Inlet Steam Temperature (TS): 287 ˚F.
2) On the Left Vertical Axis, find the Outlet Temperature of the fluid to be heated (T
Plot this point directly across on the Right Vertical Axis. Draw line between points T
3) On the Right Vertical Axis, plot the Back Pressure: 15 PSIG. Draw a horizontal line from this
point to the Left Vertical Axis.
4) Locate the point at which the above lines intersect. Draw vertical line from this point to the Bottom
Horizontal Axis to determine the Percentage of Load at which Stall occurs – 75% in this example.
=110
=74.8 %
e No. 1)
˚F (T
)
S
)
S
)
2
)
b
)
b
): 140 ˚F.
2
and T2.
S
108
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NON-ELECTRIC CONDENSATE PUMPS
Sizing & Selection
Pressure Motive Pumps
1
40 PSIG STEAM
) = 287 ˚F
(T
s
INLET TO STEAM
SUPPLY VALVE
STEAM TRAP REQUIRED
PRESSURE PSIG
3
15 PSIG
BACK PRESSURE
PUMPS
PMP REQUIRED
TEMPERATURE ˚F
3
INCHES
VACUUM
2
OUTLET WATER
TEMPERATURE (T
)
2
Figure No. 1
STALL CHART
4
75% HEAT LOAD
AT STALL
DETERMINING LOAD AT STALL
The load was not specified in the example provided. However, sufficient information was provided for its calculation.
Here is what is known:
• Steam Supply Pressure =40 PSIG
• Constant W
• Water Heating Requirements = 60 ˚F to 140 ˚F
Consulting the Engineering Section in the back of this catalog, the following equation for steam load requirements at heat
exchanger full load can be used:
Steam Load in lbs/hr=GPM x T
ater Flow =145 GPM
emp. Rise ˚F
2
=145 x (140-60)
2
=5,800 lbs/hr
At 100% open, the inlet steam valve will supply 5,800 lbs/hr for heating. We can now determine the stall load to be used for
proper sizing of the Pump-Trap Combination. From the previous section, stall was determined to occur at 75% of the full load.
Therefore:
Stall Load = 5,800 lbs/hr X 0.75 = 4,350 lbs/hr
Finally, using the guidelines previously noted within this section, the PMP and Steam Trap can be properly sized and selected.
As always, consult the factory for additional information and sizing assistance when needed.
428 Jones Boulevard • Limerick Airport Business Center • Pottstown PA • 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
www.watsonmcdaniel.com
109
NON-ELECTRIC CONDENSATE PUMPS
Customized Skid Packages
Pressure Motive Condensate Pumping Systems
Custom Fabricated Units
PUMPS
Watson McDaniel’s fully equipped ASME
qualified fabrication facility stands ready
to assist you with all of your fabrication
needs. Our engineering staff specializes in
the design of Pressure Motive Condensate
Pumping Systems for both industrial and
institutional applications. You can order
either standard packages, available from
stock, or specialized systems to meet
your specific needs.
428 Jones Boulevard • Limerick Airport Business Center • Pottstown PA • 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
www.watsonmcdaniel.com
NON-ELECTRIC CONDENSATE PUMPS
Pressure Motive Condensate Pumping Systems
DESCRIPTION OF
CUSTOM SYSTEM
This “Closed Loop” Duplex Pump
package utilizes two PMPF Pumps, two
FTE Steam Traps, and one 65 gallon
receiver tank equipped with a safety
relief valve. The Receiver is vented to
take the flash steam away at 29 PSIG
for usage elsewhere in the plant. To
accomplish this, our pilot-operatedback pressure regulator (BPR) is
mounted just off the vent line and set
to maintain the 29 PSIG pressure. If
pressure exceeds the set, the BPR unit
will dump to atmosphere thru the
supply acoustic silencer.
Another custom feature is an overflow
circuit utilizing a custom flash tank
equipped with a
for cooling applications. In the event of a
pump failure, the flooded receiver will
overflow the hot condensate into the
flash vessel where steam will vent to
atmosphere while the condensate gets
injected with cold water to safely dump
to drain.
Temperature Regulator
Custom Skid Packages
SAFETY
RELIEF VALVE
ACOUSTIC
SILENCER
FTE SERIES
STEAM TRAP
FLASH VESSEL &
CONDENSATE
COOLER
TEMPERATURE
REGULATING
VALVE
OVERFLOW
TO DRAIN
COOLED
BELOW
140 ˚F
FLASH STEAM
OUTLET
WAFER
STYLE
CHECK
VALVES
COMMON
OUTLETS
BACK
PRESSURE
REGULATOR
(BPR)
RECEIVER
PMPF
PUMPS
428 Jones Boulevard • Limerick Airport Business Center • Pottstown PA • 19464 • Tel: 610-495-5131 • Fax: 610-495-5134
www.watsonmcdaniel.com
111
ELECTRIC PUMPS
W4100 & W4200
Electric Condensate Pump
ModelW4100W4200
Tank Sizes8/15/30/45/60/95 Gal.6/15/24/36/50 Gal.
PUMPS
ConnectionsNPTNPT
Tank MaterialFabricated Carbon SteelCast Iron
Max Disch. Press.50 PSIG *50 PSIG *
TMO/TMA190˚F190˚F
Options
* Optional higher ratings available.
Mechanical & electrical alternators; gauge glass;
thermometer; discharge pressure gauges; isolation
valves; magnetic starters; 1750 RPM motors;
control panels; oversized or stainless steel receivers;
high temperature components
The primary purpose of the W4100 and W4200 electric
condensate pumps are to return condensate back to the boiler.
Pumping condensate over 190ºF is not recommended with
these pumps due to potential mechanical seal failure.
HOW IT WORKS
The float, which is connected to the switch assembly rises when
condensate enters the receiver tank. When the float rises above
its set point, it energizes the motor on the pump. Once started,
the pump will continue to run until the water level drops below
the bottom position of the float switch. There it will de-energize
the motor to shut off the pump. This cycle repeats as condensate
begins to fill the receiver tank.
FEATURES
Fabricated steel receivers (W4100) or
•
cast iron receivers (W4200)
Simplex and duplex packages
•
Bronze-fitted centrifugal pumps
•
Energy-efficient 3450 RPM motors
•
Automatic venting
•
Ceramic pump seal
•
Heavy-duty float switch
•
All steel receivers, and iron receivers over 24 gallons
•
include a threaded NPT overflow port
SAMPLE SPECIFICATION
Pump(s) shall be of the centrifugal type with two-piece
enclosed brass impeller, cast iron housing and stainless steel
motor shaft. The float switch shall be two-pole with plastic
case, stainless steel float and shafting, and double-break silver
contacts. A flat perforated brass strainer shall be provided in
the inlet of the pump fr
om the tank.
INSTALLATION
Place on an elevated, level and substantial foundation in a
clean, dry and accessible area. Locate receiver tank inlet below
lowest point of the condensate return lines.
MAINTENANCE
At regular intervals, check the motor lubrication, unless the motor
is equipped with a permanently lubricated bearing.