the answer is 2, plus another 5 to be sure
The Superheater safety valve must be the lowest set safety valve on any boiler, in order that flow through the superheater is maintained.If the drum valve were set lower the flow through the superheater would be disrupted on an overpressure.
If the superheater safety valve lifts first the excess pressure will be relieved and no damage will be done due to overheating. This is a good thing and the way it should work. If the boiler safety valve were to open first there would not be enough of a steam flow through the superheater to "cool" the tubes of the superheater which could result in severe damage. +++ ??? That does not read right at all. For a start, steam only flows through the superheater when the engine cylinder or turbine is operating. Locomotive boilers' superheaters don't have safety-valves on them, and the regulator is upstream of the superheater, but they don't overheat when the regulator is closed. The boiler safety-valve would not lessen the flow of steam through the superheater anyway - its role is to vent excess steam hence prevent over-pressure in the boiler. A safety-valve on a superheater would similarly only protect the pipes from over-pressure, not from overheating.In fact it's difficult to think of a situation in which a superheater can be overheated to the point of damage. OK Let us look at your rebuttal to my answer and I will explain why you are wrong. First you say that steam only flows through the superheater when the engine cylinder or turbine is operating. This is true but it is the first indication that you don't really understand thermodynamics. The steam is not flowing but the temperature continues to rise. Just because the safety valve lifts you don't automatically shut off the fire and this heat continues to act on the superheater raising the temperature to a level where it could damage the metal of the superheater tubes. In other words, the superheater tubes get hot from the fire and the steam gets superheated by carrying this heat away. If this heat is not removed the tube overheats and becomes damaged. But hey don't take my word for it lets see what the experts have to say. In the 40th edition of Steam, Its Generation and Use by Babcock & Wilcox Chapter 23 Page 6 under Safety and relief Valves paragraph 6 and I quote "For drum boilers with superheaters, Babcock & Wilcox (B&W) prefers to follow the Code allowed procedure of setting the safety valves so that the superheater valve(s) lift first at all loads, thereby maintaining a flow of steam through the superheater(s) to provide a measure of over-heat protection."
Propane tanks are required to have a safety relief valve. The relief valve is a safety device on the propane tank to vent excess pressure.
Safety valves are required on all closed pressure vessels.
Safety valve simmering how can setting
RUN!
safety valve
Pressure safety valve-are the valve who are designed such that it can control the pressure , like in the water blowers etc,and Temperature safety valve are those who are used to regulate the temperature like, in water boilers.
yes
water. seter valve. afromination valve. blumpkin valve
The function of steam stop valve to supply steam to steam maniform and the function safety valve to prevent the steam high pressure over.
what are type of safety valves that are used in indastrys