INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
12-13
MODEL HP
PRESSURE RE DUC ING REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
The Model HP is a heavy duty, high pressure reducing regulator used to control downstream (outlet or P2) pres sure.
Sizes are 1/2", 3/4", 1" and 1-1/2" (DN15, 20, 25 and 40). With proper trim utilization, the unit is suit able for liquid and
gaseous service. Refer to Technical Bulletin HP-TB for design conditions and selection rec om men da tions. NOT FOR
STEAM SERVICE.
SECTION II
II. INSTALLATION
CAUTION
IOM-HP
Installation of adequate overpressure pro tec tion is
recommended to pro tect the reg u la tor from overpressure and all down stream equip ment from damage
in the event of regulator failure.
CAUTION
For welded installations, all internal trim parts, seals
and diaphragm(s) must be removed from reg u la tor
body prior to welding into pipeline. The heat of
fusion welding will dam age non-metallic parts if
not re moved. NOTE: This does not apply to units
equipped with extended pipe nip ples.
1. An inlet block valve should always be installed.
2. If service application is continuous such that shut down
is not readily accomplished, it is rec ommended that
an inlet block valve, outlet block valve, and a manual
bypass valve be installed.
3. Pipe unions should be installed to allow removal from
piping.
4. An outlet pressure gauge should be located ap proxi mately ten pipe diameters downstream, and within
sight.
outlet pressure rating of the unit.
6. Clean the pip ing of all foreign material including chips,
welding scale, oil, grease and dirt before installing the
regulator. Strainers are rec om mend ed.
7. In plac ing thread seal ant on pipe ends pri or to en gage ment, ensure that excess material is re moved
and not allowed to enter the regulator upon startup.
8. Flow Direction: Install so the fl ow direction match es
the arrow cast on the main regulator body.
9. Basic Regulator - (Refer to Figure 1): Regulator may
be rotated around the pipe axis 360°. Rec om mend ed
position is with spring chamber ver ti cal upwards. Orient
such that the spring chamber vent hole does not collect
rainwater or debris.
10. Regulators are not to be direct buried un der ground.
5. All installations should include a downstream re lief
de vice if the inlet pressure could exceed the pres sure
rating of any downstream equip ment or the maximum
11. For insulated piping systems, recommendation is to not
insulate regulator.
SECTION III
III. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations register on
the diaphragm. The registering pressure is the outlet,
P2, or downstream pressure. The range spring opposes di a phragm movement. As outlet pressure drops,
the range spring pushes the dia phragm down, opening
the port; as outlet pres sure in creas es, the diaphragm
pushes up and the port opening closes.
2. A complete diaphragm failure will cause the reg u la tor
to fail open.
SECTION IV
* NOTE: Systems sequencing operations at startup,
normal operation, failure mode(s), and shutdown must assure that the pressure (P
does not exceed the pressure registering on the wetted
side of the diaphragm. Should this "pressure reversal" occur, particularly to metal diaphragms, the diaphragm may
be permanently damaged and cause improper operation.
P1 > P2 > P
Pressure reversal is normally caused by the inlet pressure
to a regulator being interrupted (automatically or manually).
IV. STARTUP
) on the spring chamber
Load
Load
CAUTION
The maximum outlet pressure is list ed on the name plate as the upper range spring pres sure level, and
is the rec om mend ed "upper operative limit" for
the sens ing diaphragm. Higher press ures could
dam age the di a phragm. Refer to HP-TB, Table 5,
for “emergency over-pressure level”. NOTE: Inlet
pres sure and outlet pressure ratings are at different
levels. (Field hydro static tests fre quent ly de stroy
dia phragms. DO NOT HYDRO STATIC TEST THRU
AN IN STALLED UNIT; ISO LATE FROM TEST.).
4. Crack open the outlet (downstream) block valve.
5. Slowly open the inlet (upstream) block valve ob serv ing
the outlet (downstream) pressure gauge. De ter mine if
the regulator is fl owing. If not, slowly rotate the regulator
adjusting screw clockwise (CW) until fl ow begins.
6. Continue to slowly open the inlet (upstream) block valve
until fully open.
7. Continue to slowly open the outlet (downstream) block
valve, especially when the downstream pip ing system
isn't pressurized. If the outlet (down stream) pressure
exceeds the desired pres sure, close the block valve
and go to Step 2, then return to Step 4.
1. Start with the block valves closed. A by pass valve may
be used to maintain out let pres sure in the down stream
sys tem without changing the fol low ing steps.
2. Relax the range spring by turning the adjusting screw
counter clockwise (CCW) a minimum of three (3) full
revolutions. This reduces the outlet (down stream) pres sure set point.
3. If it is a “hot” piping system, and equipped with a bypass valve, slowly open the bypass valve to pre-heat
the system piping and to allow slow ex pan sion of the
piping. Closely monitor outlet (down stream) pres sure
via gauge to ensure not over-pressurizing. NOTE: If no
bypass valve is in stalled, extra caution should be used
in starting up a cold system; i.e. do everything slowly.
V. SHUTDOWN
1. On systems with a bypass valve, and where sys tem
pressure is to be maintained as the reg u la tor is shut
down, slowly open the bypass valve while closing
the inlet (up stream) block valve. Fully close the inlet
(upstream) block valve. (When on bypass, the system
pressure must be constantly observed and manually
regulated. Close the outlet (downstream) block valve.
8. When fl ow is established steady enough that the outlet
(downstream) block valve is fully open, be gin to slowly
close the bypass valve if installed.
9. Develop system fl ow to a level near its expected nor-
mal rate, and reset the regulator set point by turning
the adjusting screw CW to increase outlet pressure, or
CCW to reduce outlet pressure.
10. Reduce system fl ow to a minimum level and ob serve set
point. Outlet pressure will rise from the set point of Step
9. The maximum rise in outlet pressure on decreasing
fl ow should not exceed the stated upper limit of the
range spring by greater than 10%; i.e. 400–750 psig
(27.5 –51.7 Barg) range spring, at low fl ow the outlet
pressure should not exceed 825 psig (56.8 Barg), if it
does, consult factory.
SECTION V
CAUTION
Do not walk away and leave a bypassed reg u la tor
unattended.
2. If the regulator and system are to both be shut down,
slowly close the inlet (upstream) block valve. Close the
outlet (downstream) valve only if reg u la tor re mov al is
required.
IOM-HP2
SECTION VI
VI. MAINTENANCE
WARNING
SYSTEM UN DER PRES SURE. Prior to performing
any maintenance, isolate the reg u la tor from the
system and relieve all pres sure. Failure to do so
could result in personal injury.
A. General:
1. Maintenance procedures hereinafter are based
upon re mov al of the regulator unit from the pipeline where in stalled.
2. Owner should refer to owner's procedures for
removal, handling, cleaning and disposal of nonreusable parts, i.e. gaskets, etc.
3. Refer to Figure 1 for the basic regulator and Figure
2 for a blowup of the balanced trim.
B. Diaphragm Replacement:
1. Securely install the body (1) in a vise with the spring
chamber (2) directed upwards.
WARNING
If apparent, recommend trim re mov al and inspection; go to Sub-sec tion C or D following. Reinstall
pusher plate (11).
7. Inspect pressure plate (3) to ensure no de for ma tion
due to over-pressurization. If de formed, replace.
8. Clean body (1) and diaphragm fl ange. NOTE: On
reg u la tors originally sup plied as “oxygen clean”,
Option-55, main te nance must include a level of
clean li ness equal to Cashco's clean ing stan dard
#S-1134. Con tact factory for details.
9. Place diaphragm gasket (13) on body (1) fl ange.
Position diaphragm(s) (12) into place. NOTE: Re-
fer to the quantity of diaphragms (12) incorporated
in the bill of materials list ing. Depending on the
outlet pressure lev el; mul ti ple metal diaphragms
may be “stacked”. Visually center pressure plate
(3) on diaphragm(s) (12), and set range spring (14)
onto retainer hub of pressure plate (3).
10. Place multi-purpose, high temperature grease
into depression of spring button (4) where adjusting screw bears. Set spring but ton (4) onto range
spring (14); ensure spring button is laying fl at.
NOTE: For units with range springs 120-225 psig
(8.27-15.5 Barg) and higher, position spring button
(4), thrust bearing (21) and bearing washer (22) on
top of range spring (14).
SPRING UNDER COMPRESSION. Prior to re mov ing
diaphragm fl ange bolts, relieve spring com pres sion
by back ing out the adjusting screw. Fail ure to so
so may result in fl ying parts that could cause per-
sonal injury.
2. Relax range spring (14) by turning adjusting screw
(6) CCW until removed from spring cham ber (2).
3. Draw or embed a match mark between body
casting (1) and spring chamber casting (2) along
fl anged area.
4. Remove all diaphragm fl ange nuts (9) and bolts
(8, 23).
5. Remove spring chamber (2), range spring (14),
spring button (4), pressure plate (3), diaphragm(s)
(12), and di a phragm gas ket (13), for metal diaphragm (no diaphragm gas ket (13) for composition
diaphragm). NOTE: For units with spring ranges
120-225 psig (8.27 - 15.5 Barg) and higher, also
remove the thrust bearing (21) and bearing washer
(22).
6. Remove pusher plate (11) and inspect for a fi t
which limits its travel to a vertical direction. Wear
will show as excessive wobble in push er plate (11).
11. Aligning matchmarks, place spring chamber (2)
over the above stacked parts. Install all bolts (8),
(23) and nuts (9) by hand tightening. Mechanically tightening bolting in a cross pattern that allows spring chamber (2) to be pulled down evenly.
Recommended torque values are as follows:
Regulator Size Bolt Size Metal Diaph. Comp. Diaph.
1/2", 3/4" & 1"
(DN15, 20 & 25)
1-1/2" (DN40) 7/16-20 50 Ft-lbs 30 Ft-lbs
NOTE: Never replace bolting (8 & 9) (23) with just
any bolting if lost. Bolt heads and nuts are marked
with specifi cation identifi cation mark ings. Use only
proper grades as re place ments.
12. Reinstall ad just ing screw (6) with locknut (7).
13. Pressurize with air and soap so lu tion test around
bolting (8 & 9) (23), body (1) and spring cham ber
(2) for leakage. Ensure that an outlet pressure is
maintained during this leak test of at least midrange spring level; i.e. 120-255 psig (8.27-15.5
Barg) range spring, 173 psig (11.9 Barg) test
pres sure minimum.
3/8-24 30 Ft-lbs 25 Ft-lbs
IOM-HP
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