A CORRELATION BETWEEN AN ANALYTICAL PRESSURE LOCKING THRUST CALCULATION MODEL AND TEST RESULTS OF FLEX WEDGE GATE VALVES

摘要

Pressure Locking is a phenomenon which increases the unseating force of a closed gate valve and consequently increases the risk of valve failing to open on demand. The paper discusses the primary mechanisms that can initiate pressure locking of gate valves and presents an analytical model that predicts the opening load requirements for flexible wedge gate valves under pressure locking conditions. A series of tests was performed on three typical gate valves to confirm the predictability of the model. The test results show that the model is a reasonable predictor of pressure locking induced loads and thus the model offers a useful tool for design analysis.