Cashco 345 User Manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)

MODEL 345

PRESSURE REDUCING REGULATOR

SECTION I

I. DESCRIPTION AND SCOPE

The Model 345 is a diaphragmless, heavy duty, high pressure reducing regulator used to control downstream (outlet
or P2) pres sure. Sizes are1/2", 3/4", 1" (DN15, 20, and 25 ). With proper trim utilization, the unit is suitable for liquid
and gase ous service. Refer to Tech ni cal Bulletin 345-TB for design conditions and selection recommendations.

NOT FOR STEAM SERVICE.

SECTION II

II. INSTALLATION

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 rec­ommended that an inlet block valve, outlet block
valve, and a manual bypass valve be installed.

IOM-345

12-13

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.

5. All installations should include a downstream re­lief device if the inlet pressure could exceed the
pres sure rating of any downstream equip ment or
the maximum outlet pressure rating of the unit.

CAUTION

DO NOT HYDROSTATIC TEST THRU AN IN STALLED
UNIT; ISOLATE REGU LA TOR FROM TEST. Internal
me chani cal damage could re sult. Refer to Technical
Bulletin Model 345, Table 5 for "emergency over pres sure
level" that will not do ir re pair able dam age. In ad di tion,
note on name plate that Inlet and Outlet pres sure ratings

are at dif fer ent levels.

6. Clean the piping of all foreign material including
chips, welding scale, oil, grease and dirt before
installing the regulator. Strainers are rec om ­mended.

7. In placing thread sealant on pipe ends prior to
en gage ment, assure 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): Regu la tor
may be rotated around the pipe axis 360o. Rec om­mended position is with spring chamber vertical
upwards. Orient such that the spring cham ber
vent hole does not collect rainwater or debris.

10. Regulators are not to be direct buried under­ ground.

CAUTION

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 regulator body prior to
welding into pipelne. The heat of fusion welding will dam­age non-metallic parts if not removed. NOTE: This does
not apply to units equipped with extended pipe nipples.

SECTION III

III. PRINCIPLE OF OPERATION

Movement occurs as pressure variations register on the pressure piston. The registering pressure is the outlet, P2,
or downstream pressure. The range spring opposes pressure piston movement. As outlet pres sure drops, the range
spring pushes the pressure piston down, opening the port; as outlet pres sure in creases, the pressure piston pushes
up and the port opening closes.

SECTION IV

IV. STARTUP

1. Start with the block valves closed. A bypass
valve may be used to maintain outlet pressure
in the downstream system without changing the
fol low ing steps.

2. Relax the range spring by turning the T-bar handle
ad just ing screw counter clockwise (CCW) a mini­ mum of three (3) full revolutions. This reduces the
outlet (downstream) pressure 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) pressure via gauge to assure 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.

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 pressure,
close the block valve and go to Step 2, then return
to Step 4.

8. When fl ow is established steady enough that the
outlet (downstream) block valve is fully open, be­gin to slowly close the bypass valve if installed.

9. Develop system fl ow to a level near its expected
normal rate, and reset the regulator set point by
turning the T-bar adjusting screw handle CW to
in crease outlet pressure, or CCW to reduce outlet
pressure.

4. Crack open the outlet (downstream) block valve.

5. Slowly open the inlet (upstream) block valve ob­ serv ing the outlet (downstream) pressure gauge.
Determine if the regulator is fl owing. If not, slowly
rotate the regulator T-bar ad just ing screw handle
clock wise (CW) until fl ow begins.

V. SHUTDOWN

1. On systems with a bypass valve, and where sys-

tem pressure is to be maintained as the regulator
is shut down, slowly open the bypass valve while
closing the inlet (upstream) 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.

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
pres sure on decreasing fl ow should not exceed the
stated upper limit of the range spring by greater
than 10%; i.e. 500 to1000 psig (34.5 to 68.9 Barg)
range spring, at low fl ow the outlet pressure should
not exceed 1100 psig (75.8 Barg), if it does, consult
factory.

SECTION V

CAUTION

Do not walk away and leave a bypassed regulator 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
regulator re mov al is required.

2 IOM-345

SECTION VI

VI. MAINTENANCE:

WARNING

SYSTEM UNDER PRESSURE. Prior to per form ing any
maintenance, isolate the regulator from the system and
relieve all pressure. Fail ure to do so could result in per­sonal injury.

A. General:

1. Maintenance procedures hereinafter are based
upon removal of the regulator unit from the pipe line
where installed.

2. Owner should refer to owner's procedures for
removal, handling, cleaning and disposal of non­reuseable parts, i.e. gaskets, etc.

3. Refer to Figure 1 for the basic regu la tor, metal seat
design and Figure 2 for a blow-up of the balanced
TFE trim.

B. Pressure Piston/O-Ring: Inspection/ Re place ment:

1. Securely install the body (1) in a vise with the spring
chamber (2) directed upwards.

7. Reverse steps 1 through 5 for reassembly. Make
sure spring chamber (2) is tightened fully down
against body (1).

C. Trim Replacement (For Metal Seated Units):

1. Install body (1) in a vise with the body cap (5) on
top.

2. Using a 5/16" Allen wrench, re move socket head
cap screws (21). Carefully remove body cap from
body.

3. Remove piston spring (17), piston (15 or 15.1),
cylinder (16 or 15.2) and cylinder gasket (18). In­spect parts for excessive wear, especially at seat
surfaces. Replace if worn, nicked, or depressed.

4. Remove body cap o-ring (13) and clean con tact ing
surface of body. Clean fl at mating sur faces of body
(1) to body cap (5) shoulder.

5. Clean debris from within regulator body (1) cav i ty.
Clean parts to be reused. NOTE: On regulators

originally supplied as "oxygen clean", option 345­55, maintenance must in clude a level of clean li ness
equal to Cashco's cleaning stan dard #S-1134.
Contact factory for details.

WARNING

SPRING UNDER COMPRESSION. Prior to re mov ing
spring chamber, relieve spring com pres sion by back ing
out the T-bar adjusting screw. Failure to do so may result
in fl ying parts that could cause per sonal injury.

2. Relax range spring (14) by turning T-bar ad just ing
screw handle (6) CCW to release spring compres­sion.

3. Grasp hexagon portion (w/proper wrench) of the
spring chamber (2) and turn CCW to re move.

4. Remove the thrust bearing (9), range spring (14),
and spring button (4).

5. Pull the pressure piston (3) directly out of the body.
Inspect the body quad ring (11) and body back up
ring (12). If nicked or scratched, re place. Apply
a light coating of lubricant to body quad ring (11)
when replacing.

6. Inspect pressure piston (3) to assure no de for ­ma tion due to over-pressurization. If deformed,
replace.

6. Replace cylinder gasket (18) on cylinder (16 or

15.2)

7. Reinstall the cylinder (16 or 15.2) and cylinder
gasket (18) into body cavity.

8. Slide the piston (15.1) slowly into place, as sur ing
that the piston (15.1) post slides into the pressure
piston (3).

9. Carefully place piston spring (17) directly on top of
the piston (15.1).

10. Install body cap o-ring (13) on body cap (5) and
carefully place body cap (5) into body (1). Re place
socket head cap screws (21) and tighten with a
5/16" Allen wrench. Rec om mended torque is as
fol lows:

Regulator Size Cap Screw Size Torque

1/2", 3/4" & 1"
(DN15, 20, 25)

3/8"-16-1"
skthd cap screw

50 ft./lbs.
(68 N-m)

NOTE: Never replace the socket head cap screws
(21) with just any bolting. Use only the proper size
and grade as replacement.

IOM-345 3