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What you mean by cold differential set pressure of a safety valve?
cold differential test pressure -The inlet static pressure at which a pressure relief valve is adjusted to open on the test stand. This test pressure includes corrections for service conditions of superimposed back pressure and/or temperature.
What is back pressure in refrigeration compressor terminology and what is lbp?
60 t0 65 lbs
What is difference bw condensing and non condensing steam turbines?
A condensing turbine uses all the energy from the steam going from high pressure turbine to secondary turbine to condensing turbine then sends the condensate back for reheating. where a non condensing turbine just uses the high pressure aspect of the steam then returns the low pressure stream back to be reheated. Condensng turbines utilises the entire available drop from high pressure to the vacuum in the condenser; a back pressure turbine only utilises only the top part, whereas an exhaust steam turbine utilises only th bottom part of the pressure drop. Hope that helps.
How balance disc in boiler feed pump works?
The balancing disk is fixed to and rotates with the shaft. It is separated by a small axial clearance from the balancing disk head, or balancing sleeve, which is fixed to the casing. The leakage through this clearance flows into the balancing chamber and from there either to the pump suction or to the vessel from which the pump takes its suction. The back of the balancing disk is subject to the balancing chamber back pressure, whereas the disk face experiences a range of pressures. These vary from discharge pressure at its smallest diameter to back pressure at its periphery. The inner and outer disk diameters are chosen so that the difference between the total force acting on the disk face and that acting on its back will balance the impeller axial thrust. If the axial thrust of the impellers should exceed the thrust acting on the disk during operation, the latter is moved toward the disk head, reducing the axial clearance between the disk and the disk head. The amount of leakage through the clearance is reduced so that the friction losses in the leakage return line are also reduced, lowering the back pressure in the balancing chamber. This lowering of pressure automatically increases the pressure difference acting on the disk and moves it away from the disk head, increasing the clearance. Now the pressure builds up in the balancing chamber, and the disk is again moved toward the disk head until an equilibrium is reached. To assure proper balancing in disk operation, the change in back pressure in the balancing chamber must be of an appreciable magnitude. Thus, with the balancing disk wide open with respect to the disk head, the back pressure must be substantially higher than the suction pressure to give a resultant force that restores the normal disk position. This can be accomplished by introducing a restricting orifice in the leakage return line that increases back pressure when leakage past the disk increases beyond normal. The disadvantage of this arrangement is that the pressure on the seal chamber is variable, a condition that may be injurious to the life of the seal and therefore should avoided.
What causes engine back pressure?
Usually back pressure is caused by worn piston rings, combustion gasses passing the rings into the sump, there are also some engines which have positive oil pan ventilation trough the air filter with a suction pipe (BMW engines)Back pessure goes hand in hand with light blue smoke and lack of compression.
