Search results
Results From The WOW.Com Content Network
Diaphragm valves can be controlled by various types of actuators e.g. manual, pneumatic, hydraulic, electric etc. The most common diaphragm valves use pneumatic actuators; in this type of valve, air pressure is applied through a pilot valve into the actuator which in turn raises the diaphragm and opens the valve. This type of valve is one of ...
The "box" is a cylindrical assembly, typically of bronze, comprising a sleeve threaded on one end to accept adjusting and locking nuts. A special purpose heavy-duty rubber hose attaches the stuffing box to a stern tube, also called a shaft log, that projects inward from the hull.
A separate actuator on the piping releases pressure in the line if it crosses a threshold. This releases the pressure on the back of the seal, causing the valve to open. The essential parts of a PORV are a pilot valve (or control pilot), a main valve, a pilot tube, the dome, a disc or piston, and a seat. The volume above the piston is called ...
The word poppet shares etymology with "puppet": it is from the Middle English popet ("youth" or "doll"), from Middle French poupette, which is a diminutive of poupée.The use of the word poppet to describe a valve comes from the same word applied to marionettes, which, like the poppet valve, move bodily in response to remote motion transmitted linearly.
Pilot valves are useful because they allow a small and easily operated feed to control a much higher pressure or higher flow feed, which would otherwise require a much larger force to operate; indeed, this is even useful when a solenoid is used to operate the valve. Pilot valves are often used in critical applications (e.g., emergency and SIS ...
All end-face mechanical seals have rotating elements, stationary elements, and include five basic components: [1] seal ring; mating ring; secondary sealing elements; springs; Encasing; The seal ring and mating ring are sometimes referred to as the primary sealing surfaces. The primary sealing surfaces are the heart of the end-face mechanical seal.
The internal elements of a valve are collectively referred to as a valve's trim. According to API Standards 600, "Steel Gate Valve-Flanged and Butt-welding Ends, Bolted Bonnets", the trim consists of stem, seating surface in the body, gate seating surface, bushing or a deposited weld for the backseat and stem hole guide, and small internal ...
A furnace can be lit by a small pilot flame or in some older models, by hand. Most pilot flames nowadays are lit by an ignition transformer (much like a car's spark plugs). The pilot flame in turn lights up the main flame. The pilot flame uses natural gas while the main flame can use both diesel and natural gas. When using liquid fuels, an ...