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Terms and Vocabulary

Valves

Valves are mechanical devices that are installed in pipelines to control flow or pressure. Valves are an important part of piping systems and if not properly selected and operated, they can cause operation problems. The primary valve types, classified by their function, are:

· control valves – used to control flow, pressure, liquid level, cavitation and pressure transients;

· isolation (block) valves – placed on each side of control valves and pumps, allowing them to be removed for repair or replacement;

· check valves – used to prevent reverse flow;

· relief valves – admit air to the pipe while the pipe is being drained to prevent excessive vacuum pressures and reduce the possibility of collapsing thin-walled pipes;

· air valves – designed to expel large amounts of air at low pressure during filling and release small amounts of pressurized air during operation.

(Kennedy, John L., Oil and Gas Pipeline Fundamentals, USA. 1999)

Terms and Vocabulary

Find terms which are used with the following words.

Example: flow control valve

· flow

· valve

· fluid

Compose collocations from the following words.

Example: fully developed

flow entrance velocity developed

region cross mechanic motion fully profile boundary

fluid section reverse layer

laminar turbulent