Self-acting valves

Most reciprocating compressors have inlet and outlet valves (on the piston heads) that are actuated by a pressure difference. These are called self acting valves. There are some larger multistage reciprocating piston compressors that do have camshaft-controlled valves with rotary slide valves. 

Quick-acting valves in primary circuit pipelines in combination with self-actuated localizing devices. 

An alternative way to use flash steam is to provide several, small self-contained FSHR systems, keeping the system pipework to a minimum and lagging the pipes to avoid unnecessary heat losses. Flash steam forms at the point where the pressure drops, which is at the BD valve or the valve seat of the steam trap. From this point the flash steam and condensate travel together until the flash vessel is reached. The vessel then acts as a steam-water separator. 

Numerous results concerning analyte transport/ losses were presented in the literature and these very often lead to different conclusions on where and how much is lost during transport of the analyte vapors to the ICPMS. However, there is a dear general conclusion that can be drawn from aU these studies the transport of the ETV-formed aerosol is never quantitative for any ETV device. Following Kantor s theory, the self-nucleation process can hardly take place within the aerosol itself (i.e., without any external help) and the analyte particles easily deposit onto the colder parts of the ETV interface (e.g., the walls of the transport tubing or the switch valve) that act as nucleation/condensation sites. However, this tendency can be greatly influenced by a number of external factors. 

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