Water hammer is a pressure surge when a fluid in motion is forced to stop or change direction suddenly, causing a pressure wave in the pipe. API 600 valves, which are generally designed for use in the oil and gas industry, typically have removable seats and bonnet-to-body joint connections for seals, bonnet gaskets and cover bolting.
Specialty valves for subsea operation at very high pressures and low temperatures can be designed into a system. Other things to consider are working pressure, flow rate, the specific gravity of the media and temperature. This is probably the most common check valve in use today and is a full-port design, meaning the disc, when fully open, is out of the flow stream.
Check valves are generally designed specifically with this number in mind and, depending on the size and style of check valve, this number is 1 psi to 5 psi.
Though medium-voltage variable frequency drives VFDs are proven to improve operational efficiency and reduce costs, their electronic components can be negatively affected by the harsh environmental conditions in which large drives are commonly found. Springs, discs and stems wear prematurely by not being held steady during operation.
Valves The Basics of Check Valves. Contrary to bolted bonnet valves, internal pressure applied to a pressure seal valve forces the sealing elements into tighter contact — the higher the internal pressure, the tighter the seal. Choose the Right Seal for Cryogenic Valves.
Brochures How it Works: Generally, this style of valve is considered an off-the-shelf commodity valve with little customization available. A properly sized valve will be in either the full open or closed positions. Additionally, the tilting disc design offers closing that reduces slamming.
In order for the valve to reach the full open position, it may need a lift limiter to reduce how far the disc travels.
Check Valves. If reverse flow or critical pigging operation is required, the clapper can be manually, ROV or hydraulically actuated, and held in the full open position. The media flows around it and does not require manual or automated assistance to operate. When the disc is not stable due to insufficient flow to hold it in the full open position, chattering can occur.
Check valves can be designed with specific non-slam features to reduce the noise inside a plant and wear to the seal. The higher the flow rate, the more open the valve will be until it reaches its maximum, full open position.
If the wrong type of pump is used, then the flocculants long polymer chains may be damaged by the pumping process. When the valve is 100 percent open, it will be stable in the flow and will result in reduced premature wear and failure by eliminating the effects of chatter. The main advantage of a check valve is its simple design.