Pilot operated check valve, types SV / SL...L4X

Function and configurationSV and SL valves are hydraulic pilot operated check valves in poppet type design which may be opened to permit reverse flow.These valves are used for the isolation of operati...

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Function and configuration

SV and SL valves are hydraulic pilot operated check valves in poppet type design which may be opened to permit reverse flow.

These valves are used for the isolation of operating circuits under pressure, to prevent a load from falling or creeping movements of hydraulically locked-in actuators.

Basically these valves consist of housing (1), poppet (2), compression spring (3), control spool (4) as well as a optional pre-opening ball poppet valve (5).

Type SV (without drain port)

The valve permits free-flow from A to B. In the reverse direction, the poppet (2) is held firmly on to its seat in addition to the spring force by the system pressure.

By applying pressure at control port X the control piston (4) is moved to the right. This lifts the poppet (2) from the seat, then fluid flows from B to A.

In order to ensure the valve opens due to the pressure applied to the control piston (4) a certain minimum pilot pressure is necessary.

Type SV...A...and SL...A... (with pre-opening)

This valve has a additional decompression feature. When pressure is applied at control port X the control piston (4) is pushed to the right. The ball poppet(5.1) leaves first then the poppet (2) leaves from the seat. Now the valve may also have a flow from B to A.

Because of the pre-opening there is a dampened decompression of the fluid under pressure to avoid possible pressure shocks.

Type SL... (with drain port )

The function of this valve corresponds to the valve SV.

The difference is the additional leakage port Y. The annular area of the control piston (4) is separated from port A. The pressure at port A only effects area A4 (9) of the control piston (4).

Symbols

Ordering code

Technical data

Nominal size			10	16	20	25	32
Weight	Sub plate mounting	kg	2.1		4.7		7.8
	Threaded connection	kg	2.5	5.7	5.7	10	10
Installation position			Optional
Flow direction			From A to B free, from B to A through opening
Operating pressrure		bar	To 315
Port pilot pressure		bar	5 to 315
Control capacity-Port X		cm	2.5	10.8	10.8	19.27	19.27
-Port Y(only type SL)		cm3	2	9.6	9.6	17.5	17.5
Control area-area A1		c㎡	1.33	3.46	3.46	5.72	5.72
-area A2		c㎡	0.33	0.7	0.7	1.33	1.33
-area A3		c㎡	3.8	10.17	10.17	16.61	16.61
-area A4		c㎡	0.79	1.13	1.13	1.54	1.54
Viscosity range		m㎡/s	10 to 800
Fluid temperature range		℃	-30 to +80 (NBR seal)
			-20 to+80(FKM seal)
Fluid			Mineral oil suitable for NBR and FKM seal
			Phosphate ester for FKM seal
Degree of contamination			Maximum permissible degree of fluid contamination: Class 9. NAS 1638 or 20/18/15,ISO4406

Characteristic curves (Measured at θₒᵢₗ=40℃ ±5℃, unless otherwise)

Unit dimensions

·sub-plate mounting valve

Type	size	L1	L2	L3	L4	L5	L6	L7	L8	L9	L10
SV	10	100.8	15.5	15.5	87.8	13	42.9	18.5	7.2	35.8	-
	20	135	17.7	47.7	117	18	60.3	27.5	11.1	49.2	-
	32	156.1	36.1	46.1	134	22.1	84.2	39	16.7	67.5	-
SL	10	100.8	15.5	15.5	87.8	13	42.9	18.5	7.2	35.8	21.5
	20	135	17.7	47.7	117	18	60.3	27.5	11.1	49.2	39.7
	32	156.1	36.1	46.1	134	22.1	84.2	39	16.7	67.5	59.5

Type	size	L11	L12	L13	B1	B2	B3	B4	B5	H1	H2	H3	D1	T
SV	10	21.5	-	31.8	84	66.7	46	58.8	-	51	29	36	13	23
	20	20.6	-	44.5	100	79.4	63.5	73	-	70	37	55	22	24
	32	24.6	42.1	62.7	118	96.8	75	92.8	-	85	42.5	69	32	25
SL	10	21.5	-	31.8	84	66.7	46	58.8	7.9	51	29	36	13	23
	20	20.6	-	44.5	100	79.4	63.5	73	6.4	70	37	55	22	24
	32	24.6	42.1	62.7	118	96.8	75	92.8	3.8	85	42.5	69	30	25

Unit dimensions

.threaded connection valve

Caution:

On threaded connection valves, series L4X and series 30 have different connection dimensions.

If series 30 valves need to be replaced by series L4X ones, the pitch of installation holes and the position of external tapping shall be changed.

And as for the series 30 threaded connection valves, their configuration and connection dimensions see the Ordering code on next page.

Type	Size	Ports
Type	Size	A,B	X,Y
SV	10	G1/2 M22x1.5	G1/4 M14x1.5
	16	G3/4 M27x2
	20	G1 M33x2
	25	G11/4 M42x2
	32	G11/2 M48x2
SL	10	G1/2 M22x1.5	G1/4 M14x1.5
	16	G3/ 4 M27x2
	20	G1 M33x2
	25	G11/4 M42x2
	32	G11/2 M48x2

Type	Size	L1	L2	L3	L4	L5	L6	L7	L8	L9	L10	B1	B2	B3	H1	H2
SV	10	100.8	15.5	15.5	87.8	13	56.5	10.5	33.5	22.5	17.3	87	66.7	33.4	44	22
	16;20	133	17.7	47.7	115	18	74.5	17	50.5	36	27	105	79.4	39.7	68	34
	25;32	156.1	35.7	45.7	134	22.1	101	24	84	49	18	130	96.8	48.4	86	43
SL	10	100.8	15.5	15.5	87.8	13	56.5	10.5	33.5	22.5	17.3	87	66.7	33.4	44	22
	16;20	133	17.7	47.7	115	18	74.5	17	50.5	36	27	105	79.4	39.7	68	34
	25;32	156.1	35.7	45.7	134	22.1	101	24	84	49	18	130	96.8	48.4	86	43

Unit dimensions

.threaded connection valve

Type	Size	B1	B2	B3	D1	T1	H1	L1	L2	L3	L4	L5	L6	L7	L8	L9	Inch	Metric D2
SV	10	66.5	85	40	34	14	43	27.5	18.5	10.5	33.5	49	80	116	18	116	G1/2	M22x1.5
	15	79.5	100	55	42	16	57	36.5	17.5	13	50.5	67.5	95	135	20	146	G3/4	M27x2
	20	79.5	100	55	47	18	57	36.5	17.5	13	50.5	67.5	95	135	20	146	G1	M33x2
	25	97	120	70	56	20	75	54.5	15.5	20.5	73.5	89.5	115	173	29	179	G11/4	M42x2
	30	97	120	70	61	22	75	54.5	15.5	20.5	73.5	89.5	115	173	29	179	G11/2	M48x2
SL	10	66.5	85	40	34	14	43	22.5	18.5	10.5	33.5	49	80	116	18	116	G1/2	M22x1.5
	15	79.5	100	55	42	16	57	30.5	17.5	13	50.5	72.5	100	140	20	151	G3/4	M27x2
	20	79.5	100	55	47	18	57	30.5	17.5	13	50.5	72.5	100	140	20	151	G1	M33x2
	25	97	120	70	56	20	75	54.5	15.5	20.5	84	99.5	125	183	29	189	G11/4	M42x2
	30	97	120	70	61	22	75	54.5	15.5	20.5	84	99.5	125	183	29	189	G11/2	M48X2

Note: Dimension L7 suits valve with opening pressure types "1" and "2", and dimension L9 suits valve with opening pressure types "3".

Ordering code: for threaded connection valve type SV/SL series30