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1、IS0 INTERNATIONAL STANDARD 7842 First edition 1988-12-01 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXAYHAPOjJHAR OPTAHM3AL(kiR IlO CTAHAAPTMBAlJMM Automatic steam traps - Determination of discharge capacity - Test methods Purgeurs automatiques de va
2、peur deau - D - IS0 4185, IS0 5167 and IS0 5166 for flow measure- ments. The condensate removal device shall not be modified in any way from its commercial form. 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972
3、545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- Is0 7842 : 1988 (E) 4 Test method A 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 No
4、t for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7842 : 1988 (El 4.1 Procedure NOTE - Test method A is applicable only: TV sereaus discharge measurement. Start with all valves closed. 4.1.1 Warm wthesystem by gradually opening valves 1,
5、2, 3, 4 and L 4.11 Ad deEned as a steady water level in the accumulator with the vent valve 3 partially open and a difference of 3 OC or less showing on the temperature differential indicator. 4-l-3 Observe an - h = accumulator steam pressure, in bars; - p3 = trap ink - p4 = trap at - 6, = steam sup
6、ply temperature, in degrees Celsius; - $ = water supply temperature, in degrees Celsius; - A6 = temperature differential (subcooling) between steam in the accumulator and fluid entering the trap, in degrees Celsius. I L X = steam suppty quality; in per cent: - Z = aaxm - df = time intervat, in hours
7、, minutes or seconds; - qmt = water suppfy flow-rate, in kilograms pet- hour; - gmz = steam supply flow-rafe; in kilograms per hour; - m,r: = mass of condensate and tank at sta - iR b) the maX c) the maximum temperature differential (A01 shall not exceed 3 YZ during the test; d) no individual trap i
8、nlet pressure (pa) observation shall vary by more than 1 % of the average of all observations; e). the calcuiated vent steam flow-rate (qm6) shall not ex- ceed a maximum value equal to an exit velocity of 0,31 m/s in the tank. 18.6 Repeat the operations specified in 4.1.1 to 4.1.5 as necessary to pr
9、oduce. three sets of observations which result in three calculated capacity ratings, none of which varies from the average by more than. 1.0 %. QF qmr = (m”A;mct x 3fxo where 4m3 = 4ml X (h3 -h,Y (hg -h3) qm4 is the flash steam flow in. the accumulator, in kilograms per hour; q,a is the accumulator
10、storage rate, in kilograms per hour; qm8 =:xD2x (2, -22 3600 x- At “2 mcl and mc2 are as given in 4.1.3; hl is the specl_fic enthalpy of the supply water, in kilojoules per kilogram; h2 is the specific enthalpy of the supply steam, in kilo- joules per kilogram; h3 is the specific enthalpy of saturat
11、ediwa hi-1 i 1) 1 bar = 105 Pa 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7842 : 198
12、8 (El hs is the specific enthalpy of saturated water in the ac- cumulator, in kilojoules per kilogram; At is the time interval, in seconds; v1 is the specific volume of saturated steam in the accumulator, in cubic metres per kilogram; v2 is the specific volume of saturated water in the accumulator,
13、in cubic metres per kilogram; D is the inside diameter of the accumulator, in metres; Z, is the initial accumulator tank level, in metres; Z2 is the final accumulator tank level, in metres. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA
14、Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7842 : 1988 (El 4.3 Data sheet Test Method A General information 9 10 11 12 13 14 15 15 17 18 19. 20 21 Reference used for steam/water data : . 22 Specif
15、ic enthalpy of water supply, h, = . kJ/kg 23 Specific enthalpy of steam supply, h2 = . kJ/ kg 24 Specific enthalpy of saturated liquid at steam supply pressure, hs = . 8 . kJ/kg 25 Specific enthalpy of saturated vapour at accumulator pressure, h4 = . kJ/kg 28 Specificenthalpy of saturated liquid at
16、accumulator pressure, hs = kJ/kg 27 Specific volume of saturated vapour at accumulator pressure, v, = ms/kg 28 Specific volume of saturated liquid at accumulator pressure, v2 = . ms/kg 29 Steam to heat water supply, q,3 = ,.,.,.I., kg/h 30 31 32 TestNo. :. . 2 Dateoftest:. . 3 Calculationby: Manufac
17、turersname: r SerialNo.: 5 Size: . Description and type of device : . lnsidediameterofaccumulator,D: m Averaged and corrected test data Steam supply pressure,pt = . _ bar Accumulatorsteampressure,p2= bar Trap inlet pressure,ps = . . . bar Trapoutletpressure,p4= . bar Steam supply temperature, 0; . “
18、C Water supply temperature, 02 . OC Subcooled temperature, A0 = OC Steam supply quality, X = % Changeinaccumulatorlevel,Zt -Z2= . m Water supply flow-rate, qml = -. kg/h Steam supply flow-rate, qm2 = kg/h Elapsedtime,At= . s Thermodynamic properties Calculations item 24 - Item 22 Item 18 x Item 23 -
19、 Item 24 Flash steam flow in accumulator, qm4 = . . . . . m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . , . . , . . . , . . . . . . . . , . kg/h (Item 18 + Item 29) (Item 24 - Item 26) Item 25 - Item 26 Water flow-rate to accumulator, qm5 = . . . . . . .
20、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . , . . . . . . . . %. . kg/h Item 18 + Item 29 - Item 30 Steamflowtovent,q,s= . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _. kg/h Item 19 - Item 29 + Item 30 5 Co
21、pyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7642 : 1966 (El 33 Maximum uncorrected steam
22、flow to vent, q, = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . kg/h 2827 x (Item812 Item 27 34 Ventfractionofmaximum,R = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23、 . . . . . . . . . . . . . Item 32 R= item (shall be 1 for test to be valid) 36 Accumulator storage rate, qm8 = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . kg/h 2 827 x (Item 812 x Item 17 Item 20 x Item 28 36 Dischargeflow,q,f= . . . . . . . . . . . . . . . .
24、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . kg/h (Item 18 + Item 29 - Item 30) f Item 35 37 The trap capacity determined by this test is Item 36 for - an inlet pressure of Item 11 - a discharge pressure of
25、 Item 12, and - a subcooling at the trap inlet of Item 15. 6 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license f
26、rom IHS -,-,- IS0 7842 :-I966 (El 5 Test method B Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-
27、,- IS0 7842 : 1988 (E) 5.1 Procedure Start with all valves closed. 5.1.1 Open valves 1 and 2 and fill the accumulator tank to the desired level. Close valve I. 61.2 Open valve 3 and heat the water in the accumulator tank to the desired temperature. Throttle valve 2 as required to obtain water temper
28、atures above 100 “C. Leave valve 2 open slightly while venting steam to purge air from the space above the water. Close valves 2 and 3 and open valve 4. 51.3 Open valves 5 and 6 to heat the test pipe and conden- sate removal device. Monitor and adjust the system to produce the desired pressure at th
29、e test condensate removal device. 5.1.4 When thermal equilibrium is reached, begin the test. A circulation device may be necessary to ensure uniform temperature within the tank. Do not take data until the tank level complies with that shown in figure 3. 5.1.5 Observe and record as appropriate the fo
30、llowing data: a) elapsed time, in hours, minutes or seconds; bl ambient temperature Ba, in degrees Celsius; cl barometric pressure pa, in bars; d) steam pressure and temperaturep, and 0, in bars and degrees Celsius; e) initial and final values of the following: 1) temperature differential 8, - B, in
31、 degrees Celsius, 2) inlet pressurepl, in bars; 3) back pressure, 2, in bars; f) one of the following : 11 accumulator tank levels Z, and Z2, in metres, 2) mass of condensate plus weight of tank at start and finish m, in kilograms. 5.1.6 Repeat the operations specified in 5.1.1 to 5.1.5 as necessary
32、 to produce three sets of observations which result in three calculated capacity ratings, none of which varies from the average by more than 10 %. 3 E 25 N $2 E .- fi! = 1,5 1 -,- 0 0,5 1 I,5 2 2,5 3 : Pressure (bar) ant i over Figure 3 - Maximum submergence on steam trap versus test pressure 5.2 Fl
33、ow calculations nD2 (Zl - Z,) 3600 4mf = -x x- 4 At v f where qmf is the discharge flow, in kilograms per hour; D is the inside diameter of the accumulator, in metres; At is the time interval, in seconds; vf is the specific volume of water in the accumulator, in cubic metres per kilogram; or 3600 qm
34、f = b77,2 - m,d - At where mcl is the mass of condensate plus weigh tank at start, in kilograms; mc2 is the mass of condensate plus weigh tank at end, in kilograms. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/997
35、2545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7942 : 1998 (E) 5.3 Data sheet 9 10 11 12 13 14 15 18 17 18 19 20 21 22 23 24 25 28 27 28 29 30 Mass of condensate plus weigh tank at start, mcl = kg Mass of condensate plus weig
36、h tank at finish, mc2 = . . .-.-. . kg 4 Differential pressure at start of test bar hem 18 - Item 20 Differential pressure at finish of-test bar Item 19 - Item 21 Averagedifferentialpressure . bar Item 27 + Item 28 2 Item 24 Calculations Quantityofwaterdischarged kg 71 (Item 812 (Item 22 -Item 23) -
37、x Test Method B General information Test No.-: -. . 2 Date of test : 3 Calculation by : . Manufacturersname: . Serial No, : - 5 Size: . . . Description and type of device : . lnsidediameterofaccumulator,D= . m Averaged and corrected test data Temperature of steam in the accumulator tank, B, start =
38、. _ OC Temperature of steam in the accumulator tank, 6, finish = OC Temperature of condensate to device, Bc, start = . . -. OC Temperature of condensate to device, 8, finish = . OC Temperature difference, 19 - 0, start = T Temperature difference, 8, - 8, finish = . OC Time interval, A I . .C . S Ste
39、am pressure in the accumulator tank, ps, start = . bar Steam pressure inthe accumulator-tank,_p, finish = . bar Steam pressure at device inlet, pt, start = . . bar Steam pressure at device inlet,g, finish = . _ -. . bar Steam pressure at device outlet, p2, start = bar Steam pressure at device outlet
40、, pz, finish = bar Initial level of water in the accumulator tank, 2, = _ . m Final level of water in the accumulator tank, Z2 = . m Specificvolumeofliquid,vr= . m3/kg or 9 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standar
41、ds 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7842 : 1988 (E) 31 Capacity,q,f kg/h Item 30 x 3 600 Item 15 or 32 Amount of condensate collected, . . . _ _ . . . . . . . . . . . . . . . . . . . . . . . . . . . ., . .
42、. . . ., ., ., . . . . . _ . . . . -. _ . . . . _ _ . . _ . . . kg Item 26 -Item 25 33 Capacity, qmf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -.-. . . . . . . . . . . . . _. . . . . . . . . . . . . . . . kg/h Item 32 x 3 606
43、Item 15 34 The trap capacity determined by this test is item 31 or 33 for Item 18 + Item 19 - an inlet pressure of 2 Item 20 + Item 21 - a discharge pressure of 2 , and point 13 + point 14 - a subcooling of 2 IO Copyright International Organization for Standardization Provided by IHS under license w
44、ith ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7642 : 1966 (E) 6 Reporting of results - Test method A or B Test results may be reported only if the following additional data are
45、reported : 7 Bibliography IS0 6704, Automatic steam traps - Classification. a) trap inlet pressure; bl trap outlet pressure; IS0 6943, Automatic steam traps - Production and perfor- mance characteristic tests. c) subcooling, A6. A minimum of five tests shall be used to plot any graph. The extrapolat
46、ion of any graph outside of the pressure range covered by the tests shall be clearly marked and the maximum subcooling (A&,) and minimum outlet pressure of the tests shall be noted on the graph. 11 Copyright International Organization for Standardization Provided by IHS under license with ISO Licens
47、ee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7642 : 1968 (E) UDC 621.166.6 Descriptors : hydraulic equipment, steam equipment, traps (drainage), tests, hydraulic tests, determination, flow rate. Price based on 11 uaaes Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:15 MDTNo reproduction or networking permitted without license from IHS -,-,-