LOW PRESSURE BOILER QUESTIONS AND ANSWERS

How do you determine if a boiler has sufficient safety valve capacity - Answer-The accumulation test determines if the valve will discharge all the steam pressure, without allowing the pressure to rise more than 6% more than valve setpoint If a safety valve opens at 100 psi, what pressure should it close at? What requirements governors safety valve blowdowns? - Answer-A: 96-98 psi, with no chatter, with a blowdown of no more than 4 psi of set pressure. A safety valve is limited to how many square ft of heating surface. - Answer-Any boiler with more than 500 sq ft must have two or more safety valves What is a safety valve and how does it operate - Answer-Is a device that expels all excess steam pressure from a boiler. The huddling chamber causes the valve to open fully causing a definite drop in pressure before closing. What type of stays are used in a the heads of a water tube boiler - Answer-No stays, the head of the boiler drum is shaped with a die, which would form them in the shape they would take when pressure is applied. Your fuel oil tank capacity is 20,000 and you have 10,000 left. How much do you order? - Answer-8,000 gallons. Fuel tanks cannot be filled past 90% because of overfill protection. Why are handhelds and manholes made oval instead of round. What are minimum sizes for both openings? - Answer-So they can be removed and inserted from respective openings in the boiler. Manhole 11X5 or 10 X 16 handheld 2 3/4 X 3 1/2 What is thermal efficiency? What is a good percentage? - Answer-It is the ratio of heat supplied by the fuel to the heat absorbed by the boiler. 85% How do you determine boiler capacity and what is boiler heating surface - Answer-Total heating surface determines the capacity of the boiler. Heating surface on one side and boiler water on the other. Measures from the fire side. What is the furnace volume? Is furnace volume measured in? - Answer-Furnace volume is the space available for complete combustion of the fuel before the products of combustion enter he heating absorbing section of the boiler. This varies with the type of fuel used. Measure in cubic ft How is a blowdown tank piped, how does it work and why isn't any pipe directly connected to sewer - Answer-The blowdown enters in the tank above the waterline, maintained in the tank against a splash guard. There is a vent on the top of the tank to prevent back pr