Tightness controls TC
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Tightness controls • Adjustable test period which can be adapted to different systems • Adjustable test instant allows quick system start • Maximum safety thanks to self-monitoring electronics

The tightness control TC checks the fail-safe function of both valves before each start-up or after each shut-down of a system with two safety valves. The aim is to identify an inadmissible leak on one of the gas valves and to prevent burner start. The other gas valve continues working properly and takes over the safe shut-off of the gas supply. It is used in industrial thermoprocessing equipment, on boilers and on forced draught burners. Standards ISO 13577-2, EN 746-2 and EN 676 stipulate tightness controls for capacities over 1200 kW (NFPA 86: from 117 kW or 400,000 Btu/h in conjunction...

Application examples Pz =!nternal pressure sensor of the TC for the comparison of inlet pressure pu and interspace pressure pz pd = Outlet pressure Vp = Test volume TC 1V with valVario controls Mains voltage = control voltage V1: quick or slow opening valve with start rate. V2: pressure regulator with solenoid valve. Tightness control TC 1V checks gas solenoid valves V1 and V2 and the pipe between the valves for tightness. If both valves are tight, the TC forwards the OK enable signal to the automatic burner control unit GFA. This opens valves V1 and V2 simultaneously. The burner starts. TC...

TC 2 with two gas solenoid valves Mains voltage = control voltage V1 and V2: quick or slow opening valves with start rate. TC 2 checks gas solenoid valves V1 and V2 and the pipe between the valves for tightness. If both valves are tight, the TC forwards the OK enable signal to the automatic burner control unit GFA. This opens valves V1 and V2 simultaneously. The burner starts. TC 2 with two gas solenoid valves and one auxiliary valve for discharge Mains voltage = control voltage V1 and V2: quick or slow opening valves with start rate. V3: quick or slow opening valve with start rate, nominal...

TC 2 with two gas solenoid valves and one auxiliary valve for discharge Mains voltage = control voltage V1: quick or slow opening valve with start rate. V2: any. V3: quick opening, nominal size is dependent on test volume Vp and inlet pressure pu, but is at least DN 15. TC 2 checks gas solenoid valves V1, V2, the auxiliary valve V3 and the pipe between the valves for tightness. If all the gas solenoid valves are tight, the tightness control forwards the OK enable signal to the automatic burner control unit GFA. The GFA opens the gas solenoid valves V1 and V2 simultaneously. The burner...

TC 3 in a multiple burner system with several valves installed in series TC 3 checks slow opening main valves V1 and V2 and the pipe between these valves for tightness. The test volume VP is supplied and discharged via the TC 3 auxiliary valves. Valve V2 can only be checked for tightness when the pressure downstream of V2 approximately corresponds to the atmospheric pressure and the volume downstream of valve V2 is 5 x VP. The gas solenoid valve VAS and the pressure switch DGVAS are used to relieve the pressure. The pressure switch must be adjusted in such a way so that enough pressure is...

TC 4 with two gas solenoid valves and one auxiliary valve for discharge V1: quick or slow opening valve with start rate. V2: any. V3: uick opening, nominal size is dependent on q test volume VP and inlet pressure pu, but is at least DN 15. TC 4 checks gas solenoid valves V1, V2, the auxiliary valve V3 and the pipe between the valves for tightness. It must be ensured that the interspace pz is vented during the 2-second opening time. This is not guaranteed by the gas pressure regulator downstream of V2. A relief line is thus used to discharge the test volume VP safely into the combustion...

TC 4 in a multiple burner system with several valves installed in series Tightness control TC 4 checks the central shutoff valve V1, the gas solenoid valve V2 and the pipe between these valves for tightness. Valve V2 can only be checked for tightness when the pressure downstream of V2 approximately corresponds to the atmospheric pressure. The gas solenoid valve VAS and the pressure switch DGVAS are used to relieve the pressure. The pressure switch must be adjusted in such a way so that enough pressure is relieved and no air can get into the pipework. After the thermostat/start-up signal ϑ...

Technical data TC 1, TC 2, TC 3 Electrical data Mains voltage and control voltage: 120 V AC, -15/+10%, 50/60 Hz, 230 V AC, -15/+10%, 50/60 Hz, 24 V DC, ±20%. Power consumption (all LEDs green): 5.5 W at 120 V AC and 230 V AC, 2 W at 24 V DC, TC 3: plus 8 VA for an auxiliary valve. Fine-wire fuse: 5 A, slow-acting, H, 250 V, pursuant to IEC 60127-2/5, F1: protection of valve outputs (terminals 15 and 16), fault signal (terminal 12) and supply of the control inputs (terminals 2, 7 and 8). F2: protection of safety interlock/controller enable signal (terminal 6). The input current at terminal 1...

Indicators and operating controls Electrical data Mains voltage: 110/120 V AC, -15/+10%, 50/60 Hz, 220/240 V AC, -15/+10%, 50/60 Hz, 24 V DC, ±20%. Power consumption: 10 VA for 110/120 V AC and 220/240 V AC, 1.2 W for 24 V DC. Fusing: fine-wire fuse 5 A, slow-acting, H pursuant to IEC 127, also protects the valve outputs and external operating signal. Switching current for valves/enable output: max. 5 A. External operating signal: with mains voltage, max. 5 A resistive load (UL listed: 5 A for 120 V), max. 2 A at cos 9 = 0.35 (pilot duty). Fault output: dry contact (not internally...

Maintenance cycles Tightness controls TC require little servicing. We recommend carrying out a function check once a year or twice a year in the case of biogas.

Technical Information bulletin for this product www.docuthek.com Search term: TC 12 ■ TC ■ Edition 04.17 Contact www.kromschroeder.com ^ Process Heat ^ Sales Elster GmbH Strotheweg 1 ■ 49504 Lotte (Buren) Germany Tel. +49 541 1214-0 hts.lotte@honeywell.com www.kromschroeder.com We reserve the right to make technical modifications in the interests of progress. Copyright © 2017 Elster GmbH All rights reserved.