DFT: Check Valves:

SCV® Threaded In-Line Check Valve

The DFT® Model SCV® is a corrosion resistant, dependable, versatile and economical spring-assisted, in-line check valve.

For liquid, gas or steam.

The SCV® provides tight shut-off and protects other equipment in the system from water hammer.

Stainless steel construction insures a long service life.

Documentation:
Product Specifications
(143KB PDF)

Please use the form below to request a quote:

Check Valve Operation:

A check valve allows flow in one direction and automatically prevents back flow (reverse flow) when fluid in the line reverses direction. They are one of the few self-automated valves that do not require assistance to open and close.

Check valves are flow sensitive and rely on the line fluid to open and close. The internal disc allows flow to pass forward, which opens the valve. The disc begins closing the valve as forward flow decreases or is reversed, depending on the design. The function or purpose of a check valve is to prevent reverse flow.

Internal sealing of the check valve disc and seat relies on “reverse” line pressure as opposed to the mechanical force used for on/off valves. Because of this, allowable seat leakage rates are greater for check valves than with on/off valves.

SCV® Check Valve

1/2” to 3” Line size
750 & 3600 CWP
NPT & SW ends
Stainless steel construction
Inconel® X-750 spring
Spring-assisted silent closing, non-slam
Zelon® “O” ring body seal
Horiz or vert install
Body-guided disc
Tight shutoff lapped disc & seat

DFT SCV® Check Valve

The DFT Model SCV® Check Valve is a corrosion-resistant, dependable, versatile and economical spring-assisted, non-slam check valve for a wide range of applications.

Options:

316 SS springs
Body seal weld
Soft seat
Alloy 20 body & seat (ASME 300)

Hastelloy® C body & seat (ASME 300)
NPT x socket weld ends
SCV-R (higher cracking pressure)
NACE

Whether the fluid is liquid, gas or steam, the SCV provides tight shutoff and protects other equipment in the system from water hammer.
Its stainless steel construction assures a long service life.

Pressure Temperature Rating (PSIG) (3)
A351 CF8M			Alloy 20 (CN7M)	Hastelloy® C (CW-12MW)
Temp. (F°)	750 CWP	3600 CWP	ASME 300	2-1/2"
100	750	3600	600	600
200	645	3095	520	550
250 (4)	610	2945	490	535
300	580	2795	465	520
400 (5)	535	2570	420	490
470 (6)	510

Materials of Construction
Component	750 CWP	3600 CWP
Body	A351 CF8M	A351 CF8M
Seat	A351 CF8M	A351 CF8M
Disc	A240 316	A240 316
Spring	Inconel® X-750	Inconel® X-750
Body Seal	Standard: Zelon (470°F max)	Standard: Zelon (470°F max)
Body Seal	Option: Body seal weld (700°F max)	Option: Body seal weld (700°F max)


SCV THREADED IN LINE CHECK VALVES
Part #	Size	Cold Working Pressure	Dimension A	Dimension B	Cv	Cracking Pressure CP	End Connection
8317	DN 15 0.5 in	0 to 750 psig 0 to 51.7 barg	2.68 in 68 mm	1.62 in 41 mm	7	0.29 psig 0.020 bar	NPT
8368	DN 20 0.75 in	0 to 750 psig 0 to 51.7 barg	3.00 in 76 mm	2.13 in 54 mm	13	0.24 psig 0.017 bar	NPT
8369	DN 25 1 in	0 to 750 psig 0 to 51.7 barg	3.32 in 84 mm	2.54 in 65 mm	22	0.36 psig 0.025 bar	NPT
8371	DN 32 1.25 in	0 to 750 psig 0 to 51.7 barg	3.87 in 98 mm	3.06 in 78 mm	39	0.28 psig 0.019 bar	NPT
8373	DN 40 1.5 in	0 to 750 psig 0 to 51.7 barg	4.75 in 121 mm	3.44 in 87 mm	54	0.24 psig 0.017 bar	NPT
8374	DN 50 2 in	0 to 750 psig 0 to 51.7 barg	5.00 in 127 mm	4.4 in 112 mm	93	0.42 psig 0.029 bar	NPT
8311	DN 80 3 in	0 to 750 psig 0 to 51.7 barg	6.75 in 171 mm	6.19 in 157 mm	180	0.20 psig 0.014 bar	NPT
8317SW	DN 15 0.5 in	0 to 750 psig 0 to 51.7 barg	2.68 in 68 mm	1.62 in 41 mm	7	0.29 psig 0.020 bar	Socket Weld
8368SW	DN 20 0.75 in	0 to 750 psig 0 to 51.7 barg	3.00 in 76 mm	2.13 in 54 mm	13	0.24 psig 0.017 bar	Socket Weld
8369SW	DN 25 1 in	0 to 750 psig 0 to 51.7 barg	3.32 in 84 mm	2.54 in 65 mm	22	0.36 psig 0.025 bar	Socket Weld
8371SW	DN 32 1.25 in	0 to 750 psig 0 to 51.7 barg	3.87 in 98 mm	3.06 in 78 mm	39	0.28 psig 0.019 bar	Socket Weld
8373SW	DN 40 1.5 in	0 to 750 psig 0 to 51.7 barg	4.75 in 121 mm	3.44 in 87 mm	54	0.24 psig 0.017 bar	Socket Weld
8374SW	DN 50 2 in	0 to 750 psig 0 to 51.7 barg	5.00 in 127 mm	4.4 in 112 mm	93	0.42 psig 0.029 bar	Socket Weld
8311SW	DN 80 3 in	0 to 750 psig 0 to 51.7 barg	6.75 in 171 mm	6.19 in 157 mm	180	0.20 psig 0.014 bar	Socket Weld
8317A20	DN 15 0.5 in	0 to 750 psig 0 to 51.7 barg	2.68 in 68 mm	1.62 in 41 mm	7	0.29 psig 0.020 bar	NPT
8368A20	DN 20 0.75 in	0 to 750 psig 0 to 51.7 barg	3.00 in 76 mm	2.13 in 54 mm	13	0.24 psig 0.017 bar	NPT
8369A20	DN 25 1 in	0 to 750 psig 0 to 51.7 barg	3.32 in 84 mm	2.54 in 65 mm	22	0.36 psig 0.025 bar	NPT
8371A20	DN 32 1.25 in	0 to 750 psig 0 to 51.7 barg	3.87 in 98 mm	3.06 in 78 mm	39	0.28 psig 0.019 bar	NPT
8373A20	DN 40 1.5 in	0 to 750 psig 0 to 51.7 barg	4.75 in 121 mm	3.44 in 87 mm	54	0.24 psig 0.017 bar	NPT
8374A20	DN 50 2 in	0 to 750 psig 0 to 51.7 barg	5.00 in 127 mm	4.4 in 112 mm	93	0.42 psig 0.029 bar	NPT
8311A20	DN 80 3 in	0 to 750 psig 0 to 51.7 barg	6.75 in 171 mm	6.19 in 157 mm	180	0.20 psig 0.014 bar	NPT
8317HC	DN 15 0.5 in	0 to 750 psig 0 to 51.7 barg	2.68 in 68 mm	1.62 in 41 mm	7	0.29 psig 0.020 bar	NPT
8368HC	DN 20 0.75 in	0 to 750 psig 0 to 51.7 barg	3.00 in 76 mm	2.13 in 54 mm	13	0.24 psig 0.017 bar	NPT
8369HC	DN 25 1 in	0 to 750 psig 0 to 51.7 barg	3.32 in 84 mm	2.54 in 65 mm	22	0.36 psig 0.025 bar	NPT
8371HC	DN 32 1.25 in	0 to 750 psig 0 to 51.7 barg	3.87 in 98 mm	3.06 in 78 mm	39	0.28 psig 0.019 bar	NPT
8373HC	DN 40 1.5 in	0 to 750 psig 0 to 51.7 barg	4.75 in 121 mm	3.44 in 87 mm	54	0.24 psig 0.017 bar	NPT
8374HC	DN 50 2 in	0 to 750 psig 0 to 51.7 barg	5.00 in 127 mm	4.4 in 112 mm	93	0.42 psig 0.029 bar	NPT
8311HC	DN 80 3 in	0 to 750 psig 0 to 51.7 barg	6.75 in 171 mm	6.19 in 157 mm	180	0.20 psig 0.014 bar	NPT
8303-1	DN 15 0.5 in	0 to 3600 psig 0 to 248 barg	3.16 in 80 mm	1.88 in 48 mm	36	0.62 psig 0.043 bar	NPT
8304	DN 20 0.75 in	0 to 3600 psig 0 to 248 barg	3.00 in 76 mm	2.33 in 59 mm	11	0.26 psig 0.018 bar	NPT
8305-1	DN 25 1 in	0 to 3600 psig 0 to 248 barg	3.75 in 95 mm	2.75 in 70 mm	19	0.36 psig 0.025 bar	NPT
8308	DN 50 2 in	0 to 3600 psig 0 to 248 barg	6.38 in 162 mm	4.31 in 109 mm	65	0.36 psig 0.025 bar	NPT
8303-1SW	DN 15 0.5 in	0 to 3600 psig 0 to 248 barg	3.16 in 80 mm	1.88 in 48 mm	36	0.62 psig 0.043 bar	Socket Weld
8304SW	DN 20 .75 in	0 to 3600 psig 0 to 248 barg	3.00 in 76 mm	2.33 in 59 mm	11	0.26 psig 0.018 bar	Socket Weld
8305-1SW	DN 25 1 in	0 to 3600 psig 0 to 248 barg	3.75 in 95 mm	2.75 in 70 mm	19	0.36 psig 0.025 bar	Socket Weld
8308SW	DN 50 2 in	0 to 3600 psig 0 to 248 barg	6.38 in 162 mm	4.31 in 109 mm	65	0.36 psig 0.025 bar	Socket Weld

SCV Check Valve
Class		750 CWP / 500 CWP	3600 CWP
1/2"	Dim A	2.68	3.16
	Dim B	1.62	1.88
	Weight	1.1	1.5
	Cv	0.29	0.62
	CP	7	6
3/4"	Dim A	3	3
	Dim B	2.13	2.33
	Weight	1.5	3
	Cv	13	11
	CP	0.24	0.26
1"	Dim A	3.32	3.75
	Dim B	2.54	2.75
	Weight	1.9	4.5
	Cv	22	19
	CP	0.36	0.36
1-1/4"	Dim A	3.87
	Dim B	3.06
	Weight	3.9
	Cv	39
	CP	0.28
1-1/2"	Dim A	4.75
	Dim B	3.44
	Weight	4.7
	Cv	54
	CP	0.24
2"	Dim A	5	6.38
	Dim B	4.4	4.31
	Weight	7.7	14.0
	Cv	93	65
	CP	0.42	0.36
3"	Dim A	6.75
	Dim B	6.19
	Weight	18.8
	Cv	180
	CP	0.20
Not recommended for use on discharge of reciprocating compressors.