Universal Low Pressure Check Valve Style – U3, UR

Description

The Universal Low Pressure (U3, UR) check valve is a one piece body machined from bar stock and is designed for minimum pressure drop.  The valve is light-weight, compact, and provides maintenance-free dependable service.  NPT threads are per ASME B1.20.1 and this valve is also available with ISO 7 “Rp” threads (UR). For applications above 3000 PSIG, view our UN-10 series. For applications where weld joint are required view our UN-SW series.

Many valves in this series can be supplied with B16.34 certification. Give us a call for more information.

Size & Dimension
Nominal Pipe Size Size Code A HEX SIZE B C** Orifice Diameter
3/8 C 2.16 13/16 3/8 NPT 0.348
1/2 D 2.71 1-1 1/2 NPT 0.464
3/4 F 2.95 1-1/4 3/4 NPT 0.593
1 H 3.64 1-5/8 1 NPT 0.890
1-1/4 I 3.91 2-1/4 1-1/4 NPT 1.135
1-1/2 J 4.36 2-12 1-1/2 1.385
2 K 5.85 3 2 NPT 1.555
2-1/2 L 5.50 3-3/4 2-1/2 NPT 1.555
3 M 6.25 4-1/2 3 NPT 2.025
4 N 7.13 5-1/2 4 NPT 2.560


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

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

Pressure Temperature Table
Body Material Availability Non-Shock Pressure-Temperature Rating  
316 Stainless Steel (SS)
Carbon Steel (CS)
Brass (BR)
Standard 3/8" - 3"
3000 psig @ 100°F
(1500 PSIG for o-ring seats)
4"
1500 psig @ 100°F
Alloy 20 (A2)
Alloy C-276 (HC)
Alloy 400 or MONEL®(MO)
Semi-standard
Alloy B (HB)
Titanium (TI)
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 4.3
3/4 7.2
1 14.6
1-1/4 28.8
1-1/2 31.9
2 42.0
2-1/2 50.0
3 89.0
4 140

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
SIZE PART NUMBER SS, CS & Alloys BRASS
3/8 U3C 3.0 oz. 3.3 oz.
1/2 U3D 8.5 oz. 9.1 oz.
3/4 U3F 9.6 oz. 10.1 oz.
1 U3H 1.2 lb. 1.3 lb.
1-1/4 U3I 2.9 lb. 3.2 lb.
1-1/2 U3J 3.6 lb. 3.9
2 U3K 6.5 lb. 7.2 lb.
2-1/2 U3L 9.2 lb. 10 lb.
3 U3M 14.3 lb. 15.5 lb.
4 U3N 21.7 lb. 23.9 lb.

Seat & Cracking Pressure Options
Valve Style Size Range Body Materials
Other Options
Allowable Seat Materials
Other Options
Standard Cracking Pressures.
Other Options
More Info.
Standard Spring Material
More Info.
U3 3/8" -1-1/4" 316 SS Brass AFLAS®
EPDM
"Metal to Metal"
PTFE

Buna-N
Kalrez®
Neoprene
Viton®

1/8 PSI
1/2 PSI
1.5 PSI
3.5 PSI
316 SS
U3 3/8" - 1-1/4" C. Steel AFLAS®
Buna-N
Kalrez®
"Metal to Metal"
Neoprene
PTFE
Viton®
1/8 PSI
1/2 PSI
1.5 PSI
3.5 PSI
316 SS
U3 1-1/2" - 2" 316SS
Brass
AFLAS®
Buna-N
EPDM
Kalrez®
"Metal to Metal"
Neoprene
PTFE
Viton®
1/8 PSI
1/2 PSI
1.5 PSI
316 SS
U3 1-1/2" - 2" C. Steel AFLAS®
Buna-N
Kalrez®
"Metal to Metal"
Neoprene
PTFE
Viton®
1/8 PSI
1/2 PSI
1.5 PSI
316 SS
U3 3/8" - 2" Alloy 20
Alloy C-276
AFLAS®
Buna-N
EPDM
Kalrez®
"Metal to Metal"
Neoprene
PTFE
Viton®
1/2 PSI Alloy C-276
U3 3/8" - 2" Alloy 400 or MONEL® AFLAS®
Buna-N
EPDM
Kalrez®
"Metal to Metal"
Neoprene
PTFE
Viton®
1/2 PSI Alloy 400 or MONEL®
U3 3/8" - 2" Alloy B AFLAS®
Buna-N
EPDM
Kalrez®
"Metal to Metal"
Neoprene
PTFE
Viton®
1/2 PSI Alloy B