China
Africa
Explore chapters and articles related to this topic
Valve and Actuator Technology for the Offshore Industry
Published in Karan Sotoodeh, Coating Application for Piping, Valves and Actuators in Offshore Oil and Gas Industry, 2023
Non-return valves, also called check valves, are designed and used to prevent backflow or reverse flow of liquid or gaseous media. Check valves have a flow direction marked on the body of the valve showing the direction of flow in order to keep the valve open and allow fluid to pass through it. In fact, check valves do not have any means of operation; they open by means of fluid pressure. If the fluid stops and/or returns back, the valve closes and prevents the flow from moving in the opposite direction. In short, check valves are automatic valves that open with forward flow and close against reverse flow. There are different types of check valves, such as piston, swing, dual plate and axial. Different types of check valves for topside offshore are explained below.
Fluid Transport in Thermal Energy Systems
Published in Steven G. Penoncello, Thermal Energy Systems, 2018
A check valve stops backflow by a seated disc inside the valve. When the flow is in the proper direction, the disc is moved off it’s seat. If the velocity of the flow is too small, the disc will lift, but it will not reach its stops. This results in noisy operation and premature wear of the moving parts in the valve. To alleviate this, experiments have been conducted to determine the minimum velocity required to completely move the disc to its stops, thereby eliminating noisy operation and rapid wear. The results of these experiments have been correlated to an empirical relationship given by, Vmin[ft/s]=Cρ[lbm/ft3]
Hydraulic Systems
Published in Anton H. Hehn, Fluid Power Troubleshooting, 1995
A check valve can be either a pressure control, a directional control, or both (see Fig. 2.26). Often a check valve is nothing more than a ball and seat placed between two ports. As a directional control, it has a freeflow and a no-flow direction. Flow through the seat will push the ball away and permit free flow. Flow in the other direction pushes the ball against the seat; pressure buildup forces it to seal the passage so flow is blocked.
Transient modeling of plunger lift with check valve for gas well deliquification in horizontal well
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Youliang Jia, Shuqiang Shi, Wei Tian, Bo Tan, Yacong Yang, Xuri Li
Figure 12 represents the distribution curve of liquid holdup in the tubing during the shut-in stage. It can be observed that the conventional downhole positioner cannot prevent the liquid from flowing to the bottom of the well. A gas-liquid interface was observed in the tubing. The liquid holdup below the liquid accumulation level of the gas well was greater than 0.9. However the liquid holdup above the liquid accumulation position was 0. This was observed because the liquid flows to the bottom of the well under the action of gravity in the shut-in stage, and the formation continues to supply gas and liquid to the wellbore. This ensured that the gas at the bottom of the well gradually moved to the upper part of the positioner. However, the wellbore liquid holdup distribution curve of the positioner with check valve demonstrated that curve was divided into two parts at the position of the downhole positioner. A static gas column and liquid column above the check valve were observed. The liquid holdup of the liquid column above the check valve was approximately 1. The liquid holdup above the positioner with check valve was greater compared with that of the conventional positioner. Additionally, a static gas column and liquid column were observed under the positioner.
Diagnosis of a transmission main by means of transients caused by a pump switch-off
Published in Urban Water Journal, 2018
As shown in Figure 1, downstream of the pump there is a check valve, a gate valve and a T with an off-line DN20 ball valve. Before each test, the gate valve was used to set the discharge initial value, , measured by a Venturi flow meter with a resolution of 0.2 l/s. The pressure head was acquired at the sampling frequency of 1024 Hz by means of a piezoresistive pressure transducer, with a full scale of 10 bar and an accuracy of 0.25% of the full scale. The pressure transducer was connected about 0.4 m upstream of the T derivation and about 0.2 m downstream of the gate valve (Figure 1).
Sectional lumped parameter model using bond graph and simulation for hot asphalt pipelines
Published in Journal of the Chinese Institute of Engineers, 2019
Haiying Cheng, He Hao, Ning Zhao, Zhiping Zhai
In Figure 5, Rd is the fluid resistance of the check valve; Pdi is the inlet pressure of the check valve; Pdo is the outlet pressure of the check valve; ΔPRC is the pressure loss by the fluid resistance of the check valve; Qdi is the inlet flow of the check valve; Qdo is the outlet flow of the check valve.