4th Class Power Engineering Unit A7: Introductory Fluid Handling Technology

The material designation of a valve: Select one: a. gives where the material is used b. tells what material makes up the valve c. gives the temperature to which the valve can be subjected d. tells what the material is suited for - ANS b Pipe hangers are installed at three metre intervals to: Select one: a. align the pipe, keep the pipe out of the way of foot traffic b. provide a proper drainage slope, align the pipe, allow free movement for pipe expansion c. provide a proper drainage slope, prevent leaks d. keep the pipe out of the way of foot traffic - ANS b The maximum temperature, which a non-special alloy steel valve can be used for is: Select one: a. 280 0C b. 425 0C c. 650 0C d. 1,000 0C - ANS c Before admitting any steam to a steam piping system it is imperative to first: Select one: a. warm the line up properly b. positively ensure that no water or condensate exists in the piping c. crack open the steam valve d. ensure the steam pressure is at maximum value allowed without the boiler safety valve opening - ANS b A basic ball valve must be turned this far to go from a fully closed to a fully open position: Select one: a. 1 full turn b. 3⁄4 of a turn c. 1⁄2 of a turn d. 1⁄4 of a turn - ANS d Welding together pipe size of two inch nominal size and smaller is usually done by: Select one: a. the oxygen-acetylene method b. the socket welded method c. the butt welded method d. non-pressure welders - ANS b You would use this type of valve where there is very little room between the handle and a fixed surface: Select one: a. a non-rising stem valve b. a check valve c. a ball valve d. a safety valve - ANS a Improper drainage of steam lines could: Select one: a. result in excessive steam pressures b. cause low pressure in the lines c. eventually result in water hammer d. give excessive weight to the pipe - ANS c The purpose of the stop and check valve in the boiler outlet on a boiler which is connected to a common main: Select one: a. Allows for isolation of boilers without closing stop valve b. Prevents backflow of steam from header into a boiler at lower pressure c. Check valve can prevent steam from flowing into main header d. Must be installed on every boiler - ANS b Pipe fittings, which are not clearly identified should be: Select one: a. used only with water systems b. tested before use c. rejected d. reported to the boilers branch - ANS c In order to ensure safe and continuous operation of a pressure reducing valve, the valve station should have: Select one: a. a safety valve on the downstream side b. a by-pass loop, downstream safety valve, and a downstream pressure gauge c. the piping to the station made of at least Schedule 80 piping d. a Y-strainer immediately after the valve - ANS b For varying wall thicknesses of pipe, tables are developed which give the dimensions and: Select one: a. volume in cu m b. length in cm c. weight in kg/m d. thickness in cm - ANS c The advantage of a rising spindle steam stop valve is that: Select one: a. Can tell from a distance valve position, easily lubricated and threaded part is not exposed to corrosion by high temp steam b. Can tell from a distance valve position and provides place to install isolation tags c. Can tell from a distance valve position, provides space for isolation tag and is easily lubricated d. provides space for isolation tag, easily lubricated and threaded part is not exposed to corrosion from high temperature steam - ANS a Double extra strong pipe is denoted by: Select one: a. SS b. 2S c. XXS d. DES - ANS c All markings on valves shall be: Select one: a. painted with black paint b. made with capital letters c. covered for protection d. legible - ANS d Since cast iron has a high resistance to corrosion and abrasion, it is used for: Select one: a. underground steam lines b. ash handling systems c. condensate lines d. high pressure service - ANS b ASME Code, B31.1 recommends the use of a gate valve with rising spindle as a stop valve because: Select one: a. Gate valves are easier to operate b. Gate valves have better steam control c. Gate valves can act as check valves d. Position of valve can be seen from a distance - ANS d Foamed plastics used for pipe insulation are: Select one: a. used for high temperature service b. used for refrigeration system piping only c. for lower temperature insulation purposes d. adhered directly to the pipe - ANS c A valve which has the best capability of handling slurries and fluids with high suspended solids is the: Select one: a. globe valve b. gate valve c. ball valve d. plug valve - ANS c Expansion of piping is controlled by: Select one: a. anchoring the pipe at both ends to prevent movement, installing a corrugated expansion joint b. installing a corrugated expansion joint in the line, installing an expansion bend in the line c. anchoring the pipe at both ends and installing hangers every five metres, installing an expansion bend in the line d. anchoring the pipe at both ends and installing hangers every five metres - ANS b