In the design of natural gas compressor stations, a check valve is a critical element which is commonly placed on the discharge side of the compressor to prevent reverse flow that can cause serious damage to the compressor itself and other components such as seals and bearings. One of the selection criteria of the check valve for this particular application is the valve flow characteristics in steady flow, and its dynamic characteristics in unsteady flow operation. With regards to steady flow valve Characteristics, current models for the determination of the check valve open angle versus mean flow velocity are based on semi-empirical data obtained from water tests, which were found to deviate from measurements involving fluids of relatively higher compressibility. This paper presents results of steady flow testing of an NPS 4 swing type check valve in air. Mean flow velocities versus disk angles were measured together with several local pressure measurements at the back side of the valve disk. Comparison of these results with the EPRI model and Rahmeyer’s model revealed that these two models underestimate the mean flow velocity for a given disk angle in air. A model was thus developed based on further refinement of Rahmeyer’s model, but more suitable for fluids of relatively higher compressibility, and accounts for both torque contributions: (i) from jet velocity impingement (Kv), and (ii) from back pressure distribution (Kp). The work presented here points out the need for better design of the disk shape, particularly at the lower lip, and/or the valve body in order to create a lower disk back pressure to improve the disk lifting torque at lower mean flow velocity.

1.
Chiu, C., and Kalsi, M. S., 1986, “Plant Availability Improvement by Eliminating Disc Vibrations in Swing Check Valves,” ASME/EEE Power Generation Conference Portland, OR, 86-JPGC-NE-6, October 19–23.
2.
Electrical Producers Research Institute, Application Guidelines for Check Valves in Nuclear Power Plants, EPRI NP-5479, Final Report, Jan. 1988.
3.
Horst, T., and Kalsi, M. S., 1988, “Effects of Upstream Elbows on Swing Check Valve Performance,” Proceedings of Joint ASME-ANS Nuclear Power Conference, Myrtle Beach, SC, April 17–20, pp. 15–21.
4.
Kalsi, M. S., and Horst, T., 1988, “Swing Check Valve Disc Stability Under Turbulence,” Proceedings of Joint ASME-ANS Nuclear Power Conference, Myrtle Beach, S.C., April 17–20, pp. 23–28.
5.
Kalsi, M. S., Horst, C. L., Wang, J. K., and Sharma, V., 1990, “Prediction of Check Valve Performance And Degradation in Nuclear Power Plant Systems—Wear and Impact Tests,” Report NUREG/CR-5583 prepared for U.S. Nuclear Regulatory Commission, Aug.
6.
Rahmeyer
W. J.
,
1993
, “
Sizing Swing Check Valves for Stability and Minimum Velocity Limits
,”
ASME JOURNAL OF PRESSURE VESSEL TECHNOLOGY
, Vol.
115
, Nov., pp.
406
410
.
7.
Roorda, O., and Wright, M., 1994, “Life Cycle Cost Analysis of NPS 16 and NPS 24 Check Valves,” NGTL Internal Report, November 24.
8.
Thorley, A. R. D., 1984, “The Dynamic Response of Check Valves,” Chemical Engineering, No. 402, Apr., pp. 12–15.
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