Catalog HY10-1630/US Hydraulic Accumulators

Piston Accumulators Maintenance Instructions

Hydraulic Piston Accumulators

Installation
All accumulators shipped from the factory will be The accumulator can be mounted in any
pre-charged to a nominal pressure in order to seat orientation. However, it should be rigidly mounted
the piston on the hydraulic cap. In this case the using any combination of the mounting holes
precharge will not be listed on the label. However, in provided at the hydraulic cap or proper clamps. The
some cases they will be shipped with a nitrogen hydraulic circuit, which contains a connection to the
charge, the value of which will be marked on the accumulator should be designed so that it automati-
label/nameplate. cally discharges all hydraulic fluid from the accumu-
lator when the equipment is turned off.
Keep the hydraulic port covered to keep out
foreignmaterial until ready to make the hydraulic
connections.

141 Parker Hannifin Corporation

Hydraulic Accumulator Division
Rockford, Illinois USA
Catalog HY10-1630/US Hydraulic Accumulators
Piston Accumulators Maintenance Instructions

Pre-Charging
Use an inert gas such as nitrogen for pre-charging piston
accumulators. Do not use oxygen or shop air. FIGURE 1 FIGURE 2
If water pumped nitrogen is not available, oil-pumped PART #144595XX00 PART #085122XX00
nitrogen may be used. (C.G.A. standards: Nitrogen gas
bottles for water pumped nitrogen has a right-hand valve
thread which requires charging and gauging assembly
†144595XX00 for units up to 3000 psi. Oil-pumped nitrogen
requires a left-handed valve thread (use †144596XX00). For
all 3000 psi rated accumulators, use assembly
†144595XX00 (Figure 1). For accumulators rated over
3000 psi and the precharge requirement is above 2300 psi,
use †870816XX00 (See Figure 3).
If equipment other than the above listed is used, make sure 3000 PSI UNITS
it is compatible with the gas valve assembly. Nitrogen
Charging and Gauging Assembly
source and all components must be rated for a pressure at Part Number for Cored Accumulators
least as high as the nitrogen source. It is strongly recom-
144595 XX00 Charging and Gauging Assembly consists of 10' charging
mended that the nitrogen bottle used have the appropri- (Std) hose with standard right-hand thread nitrogen fittings
ate pressure high pressure regulator (not included). (Right-Hand) adapter incorporating gas valve, bleeder valve and gas
Make sure nitrogen supply is shut off. Attach hose to chuck (less gauge). For left-hand thread nitrogen bottle
fitting, specify part number 144596XX00.
nitrogen bottle. If accumulator has a gas valve as shown in
Figure 5 follow steps A through L and skip steps F and J. If
Part Number Gauging Assembly for Cored Accumulators
accumulator has a gas valve as shown in Figure 6, follow
steps A through L and skip steps E and I. 085122XX00 Gauging device consisting of adapter incorporating gas
valve, bleeder valve and gas chuck (less gauge).
Accumulator having gas valve as per Figure 5.
(A) Remove gas valve guard and gas valve cap.
(B) Back gas chuck “T” handle all the way out (counter
clockwise) before attaching charging assembly to
accumulator gas valve.
(C) Close bleed valve.
(D) Making sure not to loop or twist the hose, attach
swivel nut to gas valve and tighten (10-15 in. lb.)
(11.5-17 cm kg).
(E) Turn gas chuck “T” handle until the gauge starts
showing the pressure in the accumulator. Do not
turn the "T" handle all the way down, as it will dam
age the valve core.
(F) For gas valves as shown in Figure 6, hold gas
valve at point “C” with one (1) wrench while un
FIGURE 3 FIGURE 4
screwing hex nut at point “D” with a second wrench. PART #870816XX00 PART #871372XX00
This will open the poppet inside the gas valve. Note: 5000 PSI UNITS
Three (3) turns will fully open the valve. Part Number Charging and Gauging Assembly for 5000 PSI
(G) Crack open nitrogen bottle valve and slowly fill Charging and Gauging Assembly consists of 10' charging
accumulator. Shut off when gauge indicates desired 870816XX00
hose with standard right-hand thread nitrogen fittings
pre-charge. (1.035-14 NGO female)adapter incorporating gas valve,
bleeder valve and gas chuck (less gauge).
(H) Let the pre-charge set for 10 to 15 minutes. This will
allow the gas temperature to stabilize. If the desired Part Number Gauging Assembly for 5000 PSI
pre-charge is exceeded, close nitrogen bottle valve,
Gauging device consisting of adapter incorporating gas
then slowly open bleed valve (Figure 1). Do not 871372XX00 valve, bleeder valve and gas chuck (less gauge).
reduce pre-charge by depressing valve core with a
foreign object. High pressure may rupture rubber
valve seat. POINT “D”
(I) When finished pre-charging accumulator, turn “T” VALVE
CORE POINT “C”
handle all the way out on gas chuck (Figure 1), then
open bleed valve. ACCUMULATOR
(J) For gas valves as shown in Figure 6, with a
wrench, tighten hex nut at point “D” to close internal
poppet (5-8 ft. lbs.) (5.7-9.2 cm kg).
(K) Hold gas valve to keep from turning, loosen swivel
nut, remove assembly. Check for precharge leak
using a common leak reactant.
(L) Replace gas valve cap (10-15 in. lbs.) (11.5-17 cm FIGURE 5 FIGURE 6
kg) and valve guard. (Gas valve cap serves as a Part #L07471000* Gas Valve with Part #L07689000* Gas Valve with
medium pressure core for 3000 psi poppet for ASME units 7, 9, 12
secondary seal.) service, and Part #L07688000* Gas bore and some 5000 psi units.
Valve with high pressure core for
† "XX" Denotes to gauge pressure. 5000 psi service.

142 Parker Hannifin Corporation

Hydraulic Accumulator Division
Rockford, Illinois USA
Catalog HY10-1630/US Hydraulic Accumulators
Piston Accumulators Maintenance Instructions

Maintenance (13) With a wrench, tighten hex nut at point “D” to close
Repair Kits (see Parts List) are available for all internal poppet (5-8 ft. lbs.) (5.7-9.2 cm kg) then open
accumulator models. When ordering repair kits, state bleed valve to relieve residual gas charge in the
complete model number from nameplate. Also specify fluid gauging assembly.
and temperature at which used. (14) Hold gas valve at point “C” with wrench and remove
swivel nut assembly.
Occasional replacement of V-o-ring seal on the piston is
generally the only maintenance required. Replacement of (15) Replace gas valve cap and tighten (10-15 in. lb.)
other seals on end caps and gas valve is recommended (11.5-17 cm kg), and install gas valve guard.
(see Kit Numbers).
Periodic checking of pre-charge pressure will detect Remove from Hydraulic System
whether V-o-ring wear is sufficient to begin reducing sealing
performance. If pre-charge is low, also check for gas valve Shut equipment down and make certain that hydraulic
and/or end seal leakage. Allowing for temperature differ- pressure at the accumulator is at zero. At this point the
ence, if any, from time of its pressure checking, pre-charge piston will be bottomed at the hydraulic end.
pressure will rise if oil gathers in the gas side and will fall if For accumulators having gas valve as shown in Figure
gas leaks into the oil side or out past gas end seals. It is 5, attach gauging assembly as shown in Figure 2 following
suggested that a check be made a week after installation, Steps 1 through 5. Then, open bleed valve until all gas pre-
and thereafter once a month. charge is relieved from accumulator. Then remove gauging
assembly and gas valve.
Pre-charge Checking Procedure For accumulators having gas valve as shown in Figure
Using appropriate valve in the hydraulic system, 6, remove gas valve guard and gas valve cap. Then hold
discharge all oil from accumulator and allow piston to valve at point “C” with one (1) wrench while unscrewing hex
bottom against hydraulic end cap. nut at point “D” with a second wrench. Wait until all gas pre-
For accumulators rated for 3000 psi or less, with cored gas charge is relieved from the accumulator and then remove
valve, use gauging assembly as shown in Figure 2 (Part gas valve.
#085122XX00). For accumulators rated over 3000 psi up to Remove accumulator from hydraulic system. Threaded
5000 psi, use assembly as shown in Figure 4 (Part holes in hydraulic cap may be used as a means of attach-
#871247XX00). ment for lifting, or use a sling around the body.
Accumulators having gas valve as per
Disassembly of Accumulator
Figure 5.
Once the gas valve is removed - lay the accumulator
(1) Remove gas valve guard and gas valve cap. horizontal and hold down with a strap wrench or in a vise.
(2) Back gas chuck “T” handle all the way out (counter Some accumulators may have both end caps threaded into
clockwise) before attaching charging assembly to the body and some units may only have the gas cap
accumulator gas valve. threaded into the body. IN BOTH CASES ALWAYS RE-
MOVE THE GAS CAP FIRST (end cap which contained gas
(3) Close bleed valve.
valve). To remove cap or caps, install three (3) pins into the
(4) Attach swivel nut to gas valve and tighten(10-15 in. lb.) holes in the cap, then, using a long bar working against the
(11.5-17 cm kg). pins, unthread the cap from the body. Remove o-rings and
(5) Turn gas chuck “T” handle until the gauge starts back-up rings from end cap.
showing the pressure in the accumulator. Do not turn Remove piston by pushing from hydraulic end with a bar.
the "T" handle all the way down, as it will damage the NEVER TRY TO REMOVE PISTON BY APPLYING COM-
valve core. PRESSED AIR AT OPPOSITE END. To remove V-o-ring
(6) To remove gauging assembly turn “T” handle all the from piston, lift seal with O-ring pick or similar tool, moving
way out on gas chuck (Figure 1), then open bleed the tool around the piston several times while using the
valve to relieve residual gas charge in the gauging other hand to work ring off the piston.
assembly.
(7) Hold gas valve from turning, loosen swivel nut, remove Cleaning
assembly. Thoroughly clean metal parts in solvent and dry with
(8) Replace gas valve cap (10-15 in. lbs.) (11.5-17 cm kg) compressed air. Clean bore of body with a clean, lint-free
and valve guard. cloth soaked in clean solvent. Bore must be clean of any
visible particles or particles detectable to touch.
Accumulators having gas valve as per
Inspection
Figure 6.
Inspect piston for cracks, burrs around o-ring grooves, or
(9) Remove gas valve guard and gas valve cap. damage. Examine body bore, using a light, for scratches or
(10) Close bleed valve. scoring. Inspect end caps for damaged threads or burrs on
(11) Attach swivel nut to gas valve and tighten o-ring grooves.
(10-15 in. lb.) (11.5-17 cm kg).
Repair and Replacement
(12) Hold gas valve at point “C” with one (1) wrench while Minor nicks, scratches or light scoring of the body bore can
unscrewing hex nut at point “D” with a second wrench. be removed by using crocus cloth. Dress bore until all
This will open the poppet inside the gas valve. Turn 2- apparent imperfections have been removed. Replace PTFE
3 times and read pre-charge. Note: Three (3) turns wear rings, V-o-rings, o-rings and their respective back-up
will fully open the valve. washers if the original assembly contained them.

143 Parker Hannifin Corporation

Hydraulic Accumulator Division
Rockford, Illinois USA
Catalog HY10-1630/US Hydraulic Accumulators
Piston Accumulators Maintenance Instructions

Reassembly ASSEMBLY TORQUE

Coat all internal parts with clean hydraulic fluid before BORE SIZE Ft. Lb.
reassembly.
It is highly recommended to use a piston starting sleeve for 2 50+ 5.0
reassembly of piston accumulators. Call the factory for price 3 90+ 7.0
and delivery. Starting sleeve dimensions are shown below. 4 160+ 10.0
Insert the piston in the starting sleeve with the dished side 6 220+ 15.0
of the piston toward the gas end. Insert the starting sleeve 7 390+ 25.0
in the accumulator tube until it rests square on the tube.
8 390+ 25.0
Use hammer and a brass rod to tap piston into place until all 9 390+ 25.0
of piston is 2 inches below beginning of honed bore. 12 390+ 25.0
Install new back-up ring first, then a new o-ring on threaded
end cap or caps and install into body bore. Care should be Install gas valve after replacing the o-ring.
exercised not to drag o-ring over threads. End cap will stop Remount accumulator and connect to hydraulic system. Pre-
against chamfer leading into honed bore (all caps must be charge accumulator to desired precharge pressure (where
tightened to proper torque as per following chart). Cap space is a problem it may be necessary to pre-charge
should be above the end of accumulator body within 1/32" to accumulator before connecting it to the hydraulic system).
3/32".

PARTS LIST
BORE
PART NUMBER A B C D E F G H J SERVICE SIZE
PSD0000002 2.375 2.375 2.110 2.025 .100 .030 1.375 1.032 7 3K,4K,5K 2
PSD0000003 3.560 2.750 3.110 3.000 .131 .030 1.750 1.312 7 3K,4K,5K 3
PSD0000004 4.750 3.250 4.110 4.030 .089 .030 2.250 1.375 7 3K 4
PSD0000005 6.000 3.500 5.112 5.002 .124 .030 2.500 1.620 7 3K 5
PSD0000006 6.875 4.375 5.864 5.782 .104 .030 3.375 1.562 7 3K 6
PSD0000007 8.250 5.000 7.150 7.001 .173 .030 4.000 2.312 7 3K 7
PSD0000009 11.000 5.500 9.150 9.001 .174 .030 4.000 2.562 7 3K 9
PSD0000012 14.375 6.375 12.105 11.876 .268 .030 4.875 3.634 7 3K 12

144 Parker Hannifin Corporation

Hydraulic Accumulator Division
Rockford, Illinois USA
Catalog HY10-1630/US Hydraulic Accumulators
Piston Accumulators Maintenance Instructions

Parts List — Hydraulic Accumulators

Item Part Description

1* Body
2* Hydraulic Cap
3 Gas Cap
4 Piston
5 V-O-Ring
5A V-O-Ring Back-Up Washers
6 PTFE Ring (Piston)
7 O-Ring
7A O-Ring Back-Up Washer
8 Gas Valve
8A Gas Valve O-Ring
9 Gas Valve Guard
9A Screw

* Some units may have these two

components welded together.
A.S.M.E. Units, 7", 9" and 12"
bore sizes, and some units rated
above 3000 PSI will have valve per
Figure 6 (Part No. L07689000*). Other
units will have gas valve per Figure 5
(Part No. L07471000*) which will contain
gas valve core Part No. 5822220000.
Use tool (Part No. 5824410000) to
remove and replace new core.

Seal Kit Numbers (Includes items 5, 5A, 6, 7, 7A, 8A)

Bore Size
Material 2" 3" 4" 6" 7" 9" 12"
Buna-N (Std.) RK0200K000 RK0300K000 RK0400K000 RK0600K000 RK0700K000 RK0900K000 RK1200K000
Maint.

Fluorocarbon RK0200E000 RK0300E000 RK0400E000 RK0600E000 RK0700E000 RK0900E000 RK1200E000

EPR RK0200D000 RK0300D000 RK0400D000 RK0600D000 RK0700D000 RK0900D000 C.F.*
Hydrogenated Nitrile RK0200H000 RK0300H000 RK0400H000 RK0600H000 RK0700H000 C.F.* C.F.*
Low Temp Nitrile RK0200Q000 RK0300Q000 RK0400Q000 RK0600Q000 RK0700Q000 RK0900Q000 C.F.*

*C.F. = Consult Factory

145 Parker Hannifin Corporation

Hydraulic Accumulator Division
Rockford, Illinois USA
Catalog HY10-1630/US Hydraulic Accumulators
Piston Accumulators Maintenance Instructions

146 Parker Hannifin Corporation

Hydraulic Accumulator Division
Rockford, Illinois USA