Cashco 8310LP User Manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL

IOM-8310HP/LP-BASIC

12-13

MODELS 8310HP AND 8310LP

PRESSURE REDUCING REG U LA TORS

SECTION l

l. DESCRIPTION AND SCOPE

The Model 8310 is a high capacity pressure reducing regulator with double seat design used to control down stream (outlet or
P2) pressure. Sizes are 1-1/2" (DN40), 2" (DN50), 2-1/2" (DN65), 3" (DN80) and 4" (DN100). With proper trim utilization, the
unit is suitable for liquid, gas eous, or steam service. Refer to Tech ni cal Bulletin 8310-TB for design conditions and selection
recommendations.

SECTION II

II. INSTALLATION

CAUTION A

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 om mend ed that
an inlet block valve, outlet block valve, and a manual
bypass valve be installed.

3. Pipe unions are recommended for NPT screwed in stal ­la tions to allow removal from piping.

4. An outlet pressure gauge should be located ap prox i­ mate ly ten pipe diameters downstream, and within
sight.

5. All installations should include a downstream re lief
device if the inlet pressure could exceed the pres sure
rating of any downstream equipment or the max i mum
outlet pressure rating of the unit.

CAUTION B

Installation of adequate overpressure pro tec tion
is recommended to pro tect the reg u la tor and all
downstream equip ment from dam age in the event
of reg u la tor failure.

SRV

Outlet
@ P

2

P

1

Supply

@ P

1

Model 8310HP or 8310 LP
Pressure Reducing Regulator

TR

Blowdown-Drain Blowdown-Drain

(Shaded portion for steam/condensate systems)

Recommended Piping Schematic For

Pressure Reducing Station

6. Clean the piping of all foreign material including chips,
welding scale, oil, grease and dirt before in stall ing the
regulator. Strainers are rec om mend ed.

7. In placing thread sealant on pipe ends prior to en­ gage ment, ensure that excess material is re moved
and not allowed to enter the regulator upon start-up.

8. Flow Direction: Install so the fl ow direction match es
the arrow cast on the body. Install an external sensing
line (1/2" O.D. (DN15) tubing minimum) from the 3/8"
(DN10) NPT con nec tion in needle valve (39) to a point
down stream, pref er a bly at gauge location. If regula­tor pipe line is ex pand ing to a larger pipe line, always
connect sensing line to the larger pipe line.

9. For best performance, install in well drained hor i zon tal
pipe, properly trapped, if a steam service ap pli ca tion.

By pass

TR

10. 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.

11. Regulators are not to be direct buried un der ground.

12. For insulated piping systems, recommendation is to not
insulate regulator.

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

IV. START-UP

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

CAUTION C

DO NOT HYDROSTATIC TEST THRU AN IN STALLED
UNIT; ISOLATE REGULATOR FROM TEST. The upper
range spring pressure level listed on the name plate is
the rec om mend ed “up per operative limit” for the sens ing
di a phragm (see Section IV. Start-up, Number 7.) High er
pres sures could cause internal damage. In ad di tion, note
on the name plate that the Inlet and Outlet pres sure and
tem per a ture ratings are at dif fer ent levels.

SECTION III

range spring pushes the di a phragm down, opening
the ports; as outlet pres sure increases, the di a phragm
push es up and the port opening closes.

2. A complete diaphragm failure will cause the reg u la tor
to fail open.

SECTION IV

7. Continue to slowly open the outlet (downstream) block
valve, especially when the downstream piping sys tem
isn’t pressurized. If the outlet (down stream) pressure
exceeds the de sired pres sure, close the block valve
and go to Step 2, then return to Step 4.

2. Relax the range spring by turning the adjusting screw
counter clockwise (CCW) (viewed from above) a min­ i mum of three (3) full revolutions. This re duc es the
outlet (downstream) pres sure set point.

3. If it is a “hot” piping system, and equipped with a by­pass valve, slowly open the bypass valve to preheat
the system piping and to allow slow ex pan sion of the
piping. Ensure proper steam trap operation, if installed.
Close ly monitor outlet (down stream) pressure via gauge
to ensure not over-pres sur iz ing. NOTE: If no bypass

valve is in stalled, extra caution should be used in start­ing up a cold system; i.e. do everything slowly.

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 clock wise (CW) (viewed from above)
until fl ow be gins.

6. Continue to slowly open the inlet (up stream) block valve
until fully open.

SECTION V

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 in stalled. NOTE: The needle

valve (39) is shipped in a full open position. If the system
is unstable due to pressure fl uctuations, slowly close
the needle valve (39) until the system becomes stable.
This needle valve (39) should never be in a fully closed
position.

9. Develop system fl ow to a level near its expected normal
rate, and reset the regulator setpoint by turning the
adjusting screw CW (viewed from above) to increase
outlet pressure, or CCW to reduce outlet pressure.

10. Reduce system fl ow to a minimum level and observe
setpoint. 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. 10-40
psig (.69-2.8 Barg) range spring, at low fl ow the outlet
pressure should not exceed 44 psig (3 Barg). If it does,
consult factory.

V. SHUTDOWN

CAUTION D

1. On systems with a bypass valve, and where system
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 (up stream)
block valve. (When on bypass, the system pres sure
must be con stant ly observed and manually reg u lat ed.)
Close the outlet (downstream) block valve.

2 IOM-8310HP/LP-BASIC

Do not walk away and leave a bypassed regulator
un at tend ed!

2. If the regulator and system are to both be shut down,
slowly close the inlet (upstream) block valve. Close the
outlet (down stream) valve only if regulator re mov al is
re quired.

VI. MAINTENANCE

WARNING 1

SYSTEM UNDER PRESSURE. Prior to performing any
main te nance, isolate the regulator from the system and
relieve all pressure. Failure to do so could result in
personal injury.

A. General:

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

2. Owner should refer to owner’s pro ce dures for
re mov al, handling, cleaning and disposal of non­reuseable parts, i.e. gaskets, etc.

3. Refer to Figure 1 for standard regulator (NOTE:

“LP” variation has larger di a phragm area than “HP”
variation). Refer to Figures 2 through 4 for option
blow-ups.

B. Diaphragm Replacement:

1. Using an overhead hoist, lift regulator on to a fl at
surface work bench.

WARNING 2

SECTION VI

8. Pry loose pressure plate (22) from diaphragm(s)
(20) and remove both. In spect to ensure no de for ­ma tion due to over-pres sur iza tion. If de formed,
replace.

NOTES: 1. Not re mov ing the pusher plate (17) or
rotating the valve plug assembly (12) will pro vide
per for mance equal to orig i nal fac to ry per for mance
when diaphragm(s) (20) is re placed with a like
diaphragm(s) (20). Refer to Section VI.C, steps
12 and 13 for correct diaphragm setting if pusher
plate (17) or stem lock nut (19) is re moved, or valve
plug as sem bly (12) is rotated.

2. Refer to quantity of diaphragm(s) (20) in cor po­ rat ed in the bill of ma te ri als listing. De pend ing on
outlet pressure level, multiple metal di a phragms
may be “stacked”.

9. Remove diaphragm gasket (21) and pusher plate gas­ket (18). Clean gasket sealing sur fac es thor ough ly.

10. Install new diaphragm gasket (21) on di a
case (14) fl ange and new pusher plate gasket (18)
on pusher plate, if required. NOTE: No gaskets

utilized with a com po si tion (soft) di a phragm).

11. Position new diaphragm(s) (20) over threaded end
of valve plug assembly (12).

12. Ensuring that the curved outer rim side of the pres­sure plate (22) rests against the diaphragm(s) (20)
directly, place the pres sure plate (22) over threaded
end of the valve plug assembly (12).

phragm

SPRING UNDER COMPRESSION. Prior to re mov ing
fl ange bolts, relieve spring compression by removing
the ad just ing screw. Failure to do so may result in fl ying
parts that could cause per son al injury.

2. Relax range spring (28) by turning ad just ing screw
(or T-bar) (32) CCW (viewed from above) until
re moved from spring chamber (13).

3. Draw or embed a match mark between di a phragm
case (14) and spring chamber cast ing (13) along
fl anged area.

4. Remove all fl ange nuts (30) and bolts (29).

5. Remove spring chamber (13), spring button (27),
and range spring (28).

6. Draw second match mark on diaphragm case
(14) fl ange in alignment with a match mark on the
threaded end of the valve plug assembly (12) to
indicate “free vertical movement” position of the
valve plug assembly (12).

7. Securing the “fl ats” on the threaded end of the
valve plug assembly (12) with ad just able wrench,
re move pressure plate nut (24) by rotating CCW
(viewed from above).

NOTE: Do not rotate the valve plug assembly (12).
The plug (12.1) and seat rings (10 & 11) have been
me chan i cal ly lapped at the factory per ANSI Class
II seat leakage and assembled to pro vide op ti mum
“free vertical movement”.

13. Install pressure plate nut (24) on threaded end of
valve plug as sem bly (12) and tighten to a torque
value of 75-80 Ft-lbs (101-108 Nm) for metal di a­ phragm, or 30-35 Ft-lbs (40-47 Nm) for com po si tion
di a phragm. Main tain align ment of match marks on
the valve plug as sem bly (12) with second match
mark on di a phragm case (14) fl ange. NOTE: Use

two fl ange bolts (29) to keep multiple di a phragms'
(20) bolt holes prop er ly aligned while tight en ing
pres sure plate nut (24). DO NOT USE FINGERS

TO HOLD DI A PHRAGMS (20) DUR ING TIGHT EN­ ING OF PRES SURE PLATE NUT (24).

14. Set range spring (28) on retainer hub of pres sure
plate (22).

15. Place multi-purpose, high temperature grease into
depression of spring button (27) where ad just ing
screw (or T-bar) (32) bears. Set spring button (27)
on to range spring (28); ensure spring button (27)
is laying fl at.

16. Aligning the match marks, place spring cham ber
(13) over the above stacked parts. In stall all fl ange
bolts (29) and fl ange nuts (30). Me chan i cal ly
tight en bolting (29) (30) in a cross pattern that al­lows spring cham ber (13) to be pulled down evenly.
Rec om mend ed torque values are as fol lows:

Model

8310HP ALL 45 ft-lbs (61 Nm) 5/8" Ø

8310LP ALL 45 ft-lbs (61 Nm) 1/2" Ø

Diaphragm

Material

Torque

Bolt
Size

3IOM-8310HP/LP-BASIC