ISO 7842 pdf download

ISO 7842 pdf download.Automatic steam traps – Determination of discharge capacity – Test methods 1 Scope and field of application This International Standard specifies two test methods to determine the discharge capacity of automatic steam traps to ISO 6552. 2 References ISO 651, Solid-stem calorimeter thermometers. ISO 652, Enclosed-scale calorimeter thermometers. ISO 653, Long solid-stem thermometers for precision use. ISO 654, Short solid-stem thermometers for precision use. ISO 4185, Measurement of liquid flow in closed conduits 一 Weighing method. ISO 5167, Measurement of fluid flow by means of orifice plates, nozzles and Venturi tubes inserted in circular cross-section con- duits running full. ISO 5168, Measurement of fluid flow – Estimation of uncer- tainty of a flow-rate measurement. 3 Test arrangements The test arrangements for condensate capacity determination are shown in figures 1 and 2. All piping and equipment shall be insulated to a value of The instruments used for the measurements shall comply with International Standards, if such standards exist, e.g. – IS0 651 , IS0 652, IS0 653 and IS0 654 for temperature measurements; – IS0 4185, IS0 51 67 and IS0 51 66 for flow measure- ments. The condensate removal device shall not be modified in any way from its commercial form. 4.1 Procedure NOTE – Test method A is applicable only: TV eaus discharge measurement. Start with all valves closed. 4.1.1 Warm wthesystem by gradually opening valves 1 , 2, 3, 4 and L 4.1 1 Ad&t! v&es I, 2 and 3 with valve 4 wide open and vaL.sedto bring the system into equilibrium. Equilibrium is; 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.t.alternative test ar- rangements for condensate measurement &that the ciiG!Se is left to the test laboratory. 4.1 4-Racord the data specified in for a minimum total of -t&sets of observations. 4.1.5’ DiiK~ the test period observations as : a) the d&&r between the maximum and minimum tank level s&till KcS mceed 50 mm; b) the maX&.rm:vtiue of the tank level shall not exceed 450 mm at am timeduring the test; 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....