Nominal Pipe Size Size Code A HEX SIZE B C** Orifice Diameter 3/8 C 2.16 1 3/8 NPT 0.348 1/2 D 2.71 1-1/4 1/2 NPT 0.464 3/4 F 2.95 1-5/8 3/4 NPT 0.593 1 H 3.64 2-1/4 1 NPT 0.890 1-1/4 I 3.91 2-3/4 1-1/4 NPT 1.135 1-1/2 J 4.36 3-1/4 1-1/2 NPT 1.385 NOTES (DIMENSIONS TABLE) *May be larger and/or round.**Consult factory for ISO 7 "Rp" threads.

316 Stainless Steel (SS) * Alloy C-276 (HC) Alloy 20 (A2) * Alloy 400 or MONEL ® (MO) Carbon Steel (CS) * Titanium (TI) Alloy B (HB)

SIZE PART NUMBER SS, CS & Alloys 3/8 U1C 5.9 oz. 1/2 U1D 11.8 oz. 3/4 U1F 1.4 lb. 1 U1H 3.5 lb. 1-1/4 U1I 5.4 lb. 1-1/2 U1J 8.1 lb. Valve weights are approximate.

Universal High-Pressure Check Valves

The Universal High Pressure (U1, R1) check valve is a one-piece body machined from bar stock with female pipe threads. This valve is normally supplied with a “metal-to-metal” seat. NPT threads are per ASME B1.20.1 and also available with ISO 7 “Rp” threads. (R1). The valve is designed and manufactured for high pressure applications. For applications below 3000 PSIG, view our UN-3 series. Many valves in this series can be supplied with B16.34 certification. Consult the factory for more information.

Size & Dimension

Nominal Pipe Size	Size Code	A	HEX SIZE B	C**	Orifice Diameter
3/8	C	2.16	1	3/8 NPT	0.348
1/2	D	2.71	1-1/4	1/2 NPT	0.464
3/4	F	2.95	1-5/8	3/4 NPT	0.593
1	H	3.64	2-1/4	1 NPT	0.890
1-1/4	I	3.91	2-3/4	1-1/4 NPT	1.135
1-1/2	J	4.36	3-1/4	1-1/2 NPT	1.385

NOTES (DIMENSIONS TABLE)*May be larger and/or round.
**Consult factory for ISO 7 "Rp" threads.

Available Materials

316 Stainless Steel (SS) * Alloy C-276 (HC)
Alloy 20 (A2) * Alloy 400 or MONEL^® (MO)
Carbon Steel (CS) * Titanium (TI)
Alloy B (HB)

Pressure Temperature Table

Body Material	Availability	Non-Shock Pressure-Temperature Rating
316 Stainless Steel (SS) Carbon Steel (CS) Alloy 20 (A2) Alloy C-276 (HC) Alloy 400 or MONEL®(MO) Alloy B (HB) Titanium (TI)	Standard	10,000 PSIG @ 100°F
	Semi-Standard
	Contact the factory for these or other materials

Seat material and spring material selection may limit the recommended service temperature.
See seat ratings, spring ratings, and body material ratings for their respective recommended service temperatures.
Consult the factory for reduced P-T rating above 100 °F. Standard spring material is 316 Stainless Steel.

Flow Data

PRESSURE DROP PSI

Size	Cv
3/8	1.9
1/2	3.5
3/4	7.2
1	14.6
1-1/4	28.8
1-1/2	31.9

FOR WATER AT 72°F

WATER FLOWRATE - GPM

Note: All flow curves and Cv values presume the valves are fully open with 1/2 PSI cracking pressure springs. Consult the factory for more information.

Valve Weights