WPC□ L- □□Accumulator

N 2 gas7MPa

Gas typeaccumulator

Special check valve(relief valve)

N2 pressure type accumu-Hydraulicpressurelator.
Equipped with a reliefvalve for preventing breakdown of device in caseof problems with circuit
pressure (high pressure).

Oil discharge outlet(relief valve operating)Accumulator model WPCSpecifications
WPC13L-G Gas pressure

Model

WPC13L-T Gas pressure

WPC40L-G Gas pressure

WPC40L-T Gas pressure

Piping mounting

Manifold mounting

Piping mounting

Manifold mounting

Mounting, piping methods
Pressure range

MPaRefer to page →229 for characteristic line diagram.

Gas capacity

cm 313Oil capacity

cm31030

Masskg1.11.6● Proof pressure：10.5 MPa● Operating temperature：0‒60°C40● Fluid used：General mineral based hydraulic oil (ISO-VG32 equivalent)● There is also a type that adopts fluorocarbon for seal sections where cutting fluid is applied, as a measure for the use ofchlorine-based cutting fluid (this is not thermal resistant specification. Model designation WPC□L-□□-V).
：Initially filled gas pressure can be set in range of 1 MPa to 6 MPa with 0.5 MPa increment. Specify gas pressure when ordering.
Example：WPC13L-T3.0 (gas pressure 3 MPa)

Dimensions

WPC13L-□□No internal filter
22.5

22.5

ø 44

Mounting details

22.5

120

Max. ø6 hydraulic port

When manifold piping, the(50)

13.5
30

23.5

50

37
Hydraulic port
(G type)O-ring P8(hardness Hs90)

mounting surface finish
must be no rougher thanRz6.3 (ISO4287:1997).

WPC40L-□□Max. 4(plug projection depth)

32

7.5

45

6.5

32

Oil discharge outlet(relief valve operating)

WPCN2 gas

62.5

Hydraulic port
(T type)
3-Rc1/4(Factory-set plug)

Hydraulicpressure

4-M630

Accumulator

Mounting hole 4-ø6.8
Spot facing ø11 depth 7.5(45)45

No internal filter

30.5

30

ø 60

Mounting details
82.5

Mounting hole 4-ø6.8
Spot facing ø11 depth 7.5

23.5

30

(50)

13.5

When manifold piping, themounting surface finish
must be no rougher thanMax. 4(plug projection depth)
53

7.5

32
45

7.5

Rz6.3 (ISO4287:1997).
6.5

Oil discharge outlet(relief valve operating)Max. ø6 hydraulic port

503730

Hydraulic port
(G type)O-ring P8(hardness Hs90)

22.5

140

Hydraulic port
(T type)
3-Rc1/4(Factory-set plug)

Hydraulicpressure

4-M632(45)● Mounting screws are not included.

228

WPC□ L- □□Accumulator

N 2 gas

7MPa

Characteristic line diagram

WPC13LWPC40LGas pressure Gas pressure Gas pressure Gas pressure

6MPa

5MPa

4MPa

3MPa

6MPa

5MPa

4MPa

3MPa

101099Gas pressure

2MPa

8765

Gas pressure

1MPa

43

Hydraulic pressure (MPa)

Hydraulic pressure (MPa)Gas pressure Gas pressure Gas pressure Gas pressure

65Gas pressure

411101MPa

3252MPa

720

Gas pressure

80510

Oil capacity (cm3)15202530

Oil capacity (cm3)This characteristic line diagram represents theoretical values.

Model selection example
Condition (estimated temperature drop：20℃ )Hydraulic pressure：PValve & hydraulicpressure equipment

6 MPa

Inner diameter ø6×0.8 m×8 pieces
VCB：1 piece, VRG：2 pieces

WPC40L

Selection procedure

Gas pressure Gas pressure

4MPa101. Calculation of circuit capacity
Clamping capacity：8.9×2.35×8 = 167 cm3
Pressure bearing area Stroke

Hydraulic pressure(MPa)

4. Verification of hydraulic pressure and residual discharge amount ( 2) after temperature change
Select the one whose hydraulic pressure drop after temperature change is low
and residual discharge amount ( 2) satisfies the marginal oil amount ( 3). Readoff characteristic line diagram.
The hydraulic pressure after temperature change drops to 4.2 MPa with 2 MPa
gas pressure (P2), to 4.7 MPa with 3 MPa gas pressure (P3), and to 4.9 MPa with 4
MPa gas pressure (P4), respectively.
The residual discharge amount ( 2) is 20.9 cm3 for 2 MPa gas pressure (V2), 14.2
cm3 for 3 MPa (V3), and 7.5 cm3 for 4 MPa (V4), respectively.
Here, select WPC40L-□4 whose pressure drop is low.
5. Select piping method.
1：WPC13L is also available. Likewise, select appropriate one in consideration of steps 3 and 4.
2：For when the temperature decreases. If the temperature increases, check theabsorption amount.
3：Allow adequate margin for residual discharge amount after temperaturechange, as there may be margin of error with gas filling pressure. Marginal oil
amount : About 2.0 cm3Gas pressure

2MPa

7Hydraulicpressure: P65432

2. Selection of oil capacity
Select the equipment having oil capacity capable of keeping volumetric change.
Volumetric change is obtained by using formula shown below.
ΔV＝V×ΔT×α ΔV：Volumetric change (cm3) V：Circuit capacity (cm3)
ΔT：Temperature change (℃ ) α：Thermal expansion coefficient (7.8×10-4)
ΔV＝ 372×20×7.8×10-4＝5.8 cm3Here, WPC40L is selected as an example ( 1).
3. Selection of gas pressure
Select the pressure whose oil discharge amount ( 2) under hydraulic pressure
satisfies ΔV calculated in step 2. Read off characteristic line diagram.
If the hydraulic pressure of the clamping circuit is 6 MPa, select gas pressure 2MPa, 3 MPa, or 4 MPa.

98Qty

Piping capacity：0.283×80×8＝181 cm3Valve & hydraulic equipment capacity：8×3＝24 cm3(Perform calculation with capacity of 8 cm 3 for each of valves and hydraulicequipment in hydraulic circuit, when using Pascal product.)Circuit capacity：167＋181＋24＝372 cm33MPa10510154MPa Discharge amount3MPa202530

Accumulator

CTU06×8 pieces Piping

Oil capacity(cm3)

Absorption amountAbsorption
amountDischarge amount
Discharge amount

2MPa

Absorption amount

WPC40L
Hydraulic pressure(MPa)

Gas pressure Gas pressure

4MPa

103MPa9Gas pressure

8

Hydraulicpressure：PWPC
N2 gasWorking clamp

2MPa

7

Hydraulic pressure after
temperature change：P4

6
5

Hydraulic pressure after
temperature change：P3

4

Hydraulic pressure after
temperature change：P232104MPa

5Residual discharge
amount (V4)1015ΔV=5.8

Absorption amount

203MPaResidual discharge
amount (V3)2MPaResidual discharge amount (V2)

ΔV=5.82530

Oil capacity(cm3)

Absorption
amountΔV=5.8Absorption amountTo download CAD data / To get updated information, visit www.pascaleng.co.jp229