The Yoshitake SCV-3 is a flangeless wafer type check valve designed to prevent fluid backflow. It is widely used in steam or water (hot water) piping and is highly effective in preventing water hammer.

Features

• Flangeless wafer type applicable for various flange standards, eliminating the need for measuring devices.
• Can be connected in any direction (horizontal or vertical).

Specifications

Application	Steam, Cold and hot water
Maximum pressure	2.0 MPa
Applicable temperature	5-220 °C
Minimum opening pressure	0.003 MPa
Body Material	Stainless steel (SCS14A)
Disc Material	Stainless steel (SCS14A)
Connection	Wafer

WARNING

A small amount of fluid leaks at the valve seat. It should not be used for applications requiring complete closing. The product cannot be disassembled.

Structure, Dimensions and Weights

No.	Part name	Material
1	Body	Cast Stainless Steel (SCS14A)
2	Disc	Cast Stainless Steel (SCS14A)
3	Spring	Stainless Steel (SUS316)
4	Spring Plate	Stainless Steel (SUS316)

Nominal size	$\phi$ d	$\phi$ d_1	L	$\phi$ D	$\phi$ D_1	A	Weight (kg)
15A	15	35	16	43	28	63	0.2
20A	20	45	19.5	53	35	69.5	0.3
25A	25	51	22	63	41.5	80.5	0.4
32A	32	60.5	28	72.5	49.5	90.5	0.7
40A	40	70	31.5	82	57.5	101	0.9
50A	50	90	40	95.5	76	115	1.5
65A	65	102	45	116	87	142	2.2
80A	80	121	50	129.5	105.5	153.5	2.9
100A	100	145	60	154.5	128	180	4.5

Pressure Loss

Connectable Flange Standards

Nominal size	JIS 5K	JIS 10K	JIS 16K	JIS 20K	ASME 125lb	ASME 150lb	ASME 250lb	ASME 300lb	PN 6	PN 10	PN 16	PN 25	PN 40
15A	○	○	○	○	×	○	×	○	○	○	○	○	○
20A	○	○	○	○	×	○	×	○	○	○	○	○	○
25A	○	○	○	○	○	○	○	○	○	○	○	○	○
32A	○	○	○	○	○	○	○	○	○	○	○	○	○
40A	×	○	○	○	○	○	○	○	○	○	○	○	○
50A	×	○	○	○	○	○	○	○	○	○	○	○	○
65A	○	○	○	○	○	○	○	○	○	○	○	○	○
80A	×	○	○	○	○	○	○	○	○	○	○	○	○
100A	×	○	○	○	○	○	○	○	×	○	○	○	○

Note: "○" means connectable, "×" means not connectable.

Installation and Operation

Precaution for Installation

1. Before connecting the product in the piping, be sure to remove foreign substances and scale from the piping. Failure to do so causes valve seat leakage.
2. Check the direction of the product so that the fluid flowing and the arrow marked on the product are in the same direction. Wrong direction prevents fluid from flowing.
3. Connect the product to the piping so that excessive load, torque, or vibration cannot be applied to the product. Connect it firmly to avoid fluid leakage, burns, or property damage.

On installation, align the center part of the product with that of the flange by making the fin-shaped part contact with the bolt as indicated below.

Precaution for Operating Procedure

Before leading fluid, make sure that there is no danger when the fluid flows to the end of the piping. If tightening is not secured, hot fluid may spout out.

Parts Required for Installation

Bolts, nuts, and gaskets are required to install the SCV-3.

Gasket Installation Notice

The inlet diameters of the gasket differ between the inlet side and the outlet side. Refer to the table below to avoid piping mistakes, which can cause external leakage. Be sure to use proper gaskets usable for the max. pressure of 2.0 MPa.

Nominal size	Inlet Gasket Outer Dia.	Inlet Gasket Inner Dia.	Inlet Qty	Outlet Gasket Outer Dia.	Outlet Gasket Inner Dia.	Outlet Qty	Gasket Material	Bolt Dimension × Length	Bolt Qty
15A	$\phi$ 58	$\phi$ 22	1	$\phi$ 58	$\phi$ 28	1	Non Asbestos	M12×70	4
20A	$\phi$ 63	$\phi$ 28	1	$\phi$ 63	$\phi$ 35	1	Non Asbestos	M12×75	4
25A	$\phi$ 74	$\phi$ 35	1	$\phi$ 74	$\phi$ 42	1	Non Asbestos	M16×80	4
32A	$\phi$ 84	$\phi$ 43	1	$\phi$ 84	$\phi$ 50	1	Non Asbestos	M16×90	4
40A	$\phi$ 89	$\phi$ 49	1	$\phi$ 89	$\phi$ 58	1	Non Asbestos	M16×95	4
50A	$\phi$ 104	$\phi$ 61	1	$\phi$ 104	$\phi$ 77	1	Non Asbestos	M16×100	4
65A	$\phi$ 124	$\phi$ 84	1	$\phi$ 124	$\phi$ 88	1	Non Asbestos	M16×110	4
80A	$\phi$ 134	$\phi$ 90	1	$\phi$ 134	$\phi$ 106	1	Non Asbestos	M16×120	8
100A	$\phi$ 159	$\phi$ 115	1	$\phi$ 159	$\phi$ 129	1	Non Asbestos	M16×130	8

Note: The inlet gasket is equivalent to JIS B2404 Table 4 10K dimensions. Thickness is 1.5mm.

Maintenance and Troubleshooting

Precaution for Maintenance

Completely discharge the internal pressure from the valves, lines, and equipment, and cool the valve down to a level where you can touch it with bare hands before disassembly and inspection.

Trouble	Cause	Remedy
Fluid does not flow.	1. Contact surface of body and disc is stuck. 2. Installation direction is wrong.	1. Replace the product if disc does not move. 2. Confirm the arrow on the product and install it correctly.
Fluid flows back.	1. Contact surface of body and disc is worn away. 2. Internal parts are damaged.	1. Replace the product. 2. Replace the product.