ASME PTC 39:2005 pdf free dwonload

ASME PTC 39:2005 pdf free dwonload.Steam Traps.
2-1 GENERAL
For terms and definitions not included in this Section, reference should he made to ASME l’TC 2, Cede on Definitions and Values.
2-2 STEAM TRAP
A device which permits the removal of condensate and air and other noncondensible gases, for steam systems at or below saturated steam temperature, and prevents or limits the discharge of live steam.
2-3 CAPACITY OF A STEAM TRAP
The amount of condensate per unit time which will be discharged continuously from the steam trap under specified conditions of pressure differential and inlet subcooling. Capacity is expressed in units of pounds mass per hour or kilograms per hour.
2-4 PRESSURE
Pressure is expressed in units of pounds force per square inch or pascals.
(a) Absolute pressure is the algebraic sum of the atmospheric pressure and gage pressure.
(b) Atmospheric pressure is the force per unit area exerted by the atmosphere. Standard atmospheric pressure is 760 mm of mercury at 0°C. This is equivalent to 101.325 kPa and 14.696 psia.
(c) Gage pressure is pressure measured with respect to the atmospheric pressure.
(d) Inlet pressure is the gage pressure measured at the steam trap inlet.
(e) Discharge pressure is the gage pressure measUred at steam trap outlet.
(h) Record air pressure P3 and temperature T3 on Form 8. Open the inlet valve V3, the outlet valve V4, and start the test timing device simultaneously. Adjust the pressure regulating valve (PRV), if required, to maintain P2 at the desired steam test pressure.
(1) Stop the test when T2 is 10F (6 K) less than the dosing point as defined by the capacity test procedure in para. 4-8, and record the test time interval, t, on Fom 8.
(j) Repeat (b) through (i) as necessary to produce three sets of observations, which result in three calculated flow rates, none of which vary from the average by more than 10%.
4-9.6 In-Process Test
(a) Measure and record on Form 8 the volume (VAT) contained in the air accumulator and piping bounded by valves V3, V4, V5, and V6.
(h) Start with all valves in the closed position and activate electronic temperature indicating/recording devices, if used.
(c) Open valves V4, V7, and water valve V6 to cool the air accumulator to ambient temperature.
(d) Close the water valve, V6, and allow the air accumulator to drain. The air valve, V5, may be opened to facilitate draining and drying the air tank.
(e) Close valve V5 if used, and valves V4 and V7, and attach the test device.
(f) Open the vent valve, VI, and V3, and slowly adjust the steam pressure regulator, PRy, such that P1 is set at the desired test pressure. Verify temperature T1 is at saturation temperature corresponding to the test pressure, I’, and record P1 and T1 on Form 8.
NOTE: The vent valve can be throttled to a minimum flow to maintain tabIe steam prv.ure and temperature conditkm.
(g) Close V3, open valve V5, and adjust the air accumulator pressure P3 to approximately 80% of the steam test pressure P1 using the air regulator (AR). Close valve V5.
(h) Open V2 to allow the steam piping and the test device to warm up. and verify the test device is operating properly and discharging condensate.
(I) Record the air pressure, P3. and temperature, Ti. on Form 8. Simultaneously close valve V2, open valves V3 and V4, and start the test timing devices. Adjust the pressure regulating valve, PRy, as required to maintain P2 at the desired steam test pressure.