Article Index

Relief valve(Safety Relief Valve)- A type of valve used to automatically relieve the pressure in a system or vessel actuated by the pressure upstream of the valve and characterized by opening pop action with further increase in lift with an increase in pressure.

Residual fuels- Bunker C oil -/Fuel Oil No. 6. /Residual Heavy Fuel Oil/ Bunker C Fuel Oil/ -of high viscosity commonly used in marine and stationary steam power plants Products remaining from crude petroleum by removal of some of the water and an appreciable percentage of the more volatile hydrocarbons.

Resin- A sticky bead like flammable hydrocarbon organic substance, insoluble in water, used in chemical exchange for softeners and dealkalizers.

Return flow oil burner- Atomizing oil burner that withdraws part of the oil supplied to the atomizer and returns it to be stored or to the line supplying it.

Ringelmann chart- Grid series for determining smoke density in stack gas streams. The series of rectangular grids consists of 4 grids of black lines; varying widths printed on a white background and is used as a method for measuring of blackness.

Rotary oil burner- Atomization is accomplished in a burner by feeding oil to the inside of a rapidly rotating cup.

Saddle- A support casting.

Safe working pressure- See "Design Pressure." The pressure used in the design of a boiler for safe operations.

Safety valve- Prevents boiler pressure from rising above the setting of the valve by relieving excessive steam pressure, guarding against hazards of over pressure.

Safety valve drain-  A hole required through the body below the valve-seat level in the safety valves that are larger than 2 in., used to prevent condensate from collecting.

Safety valve escape- A pipe that discharges steam from a safety valve to a safe area.

Safety valve lifting lever- A lever for lifting a safey valve from it's seat.

Safety relief valve- Is used for the purpose of relieving the boiler pressure when it exceeds the MAWP (maximum allowable working pressure) and thereby prevent an explosion

Safety shut off valve- Features a springing action that shuts off the valve automatically when a problem has been detected and opens the electric current to shut off the valve until it is fixed.

Sampling- The removal of a portion of a material for examination or analysis.

Saturated air- Air that contains the maximum amount of water vapor it can hold at its temperature and pressure. 100% humidity.

Saturated steam- Steam at the same temperature as the water from which it was formed.

Saturated temperature(Boiling point)-The temperature at which evaporation occurs at a particular pressure.

Saturated water- A mixture of dry air and water vapor at its maximum concentration for the prevailing temperature and pressure. Water at its boiling point.

Scale- Hard water deposits caused by improper boiler water treatment.

Secondary treatment- Treating the water after the initial treatment of the boiler feedwater.

Sediment- Solid material that settles in water at the bottom of the boiler.

Self-supporting steel stacks- A steel stack of strong enough to support itself without using lateral support.

Service water- Is water that has been chemically treated for use in boiler or other industrial processes.

Shell- The cylindrical exterior of a steam boiler forming a case.