Honeywell Kromschroder TC1 TC2 TC3 Valve Proving Controls

  • The TC 1 is engineered to mount directly to Valvario controls.
  • TC 2 models are used to perform tightness checks on quick-opening valves. An adapter plate is provided for installation of the TC 2.
  • TC 3 models are universal devices for quick- and slow-opening gas solenoid and mechanical valves of any nominal size.


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 with a visual indicator). Pre purge of the combustion chamber can be dispensed with under certain conditions in accordance with EN 746-2, if a tightness control is used. In this case, the system must be vented into a safe area.

 TC 1V, TC 1C
Tightness control TC 1V can be directly flange mounted to all valVario controls. There is only one version for all sizes.

TC 1C can be used for combination controls CG 1 to 3. An adapter plate is supplied for installation.

TC 2 and TC 4
Tightness controls TC 2 and TC 4 can be used with gas solenoid valves of any nominal size, which are quick opening or slow opening with start rate. It is possible to conduct a tightness test on pneumatically operated or slow opening valves without start rate by using additional auxiliary valves.

Slow opening motorized valves VK up to DN 65 which are directly flanged together can also be checked by TC 2 and TC 4 within a temperature range of 0 to 60°C (32 to 140°F).

An adapter plate is provided for installation of the TC 2.

TC 3
Tightness control TC 3 is a universal device for quick and slow opening gas solenoid valves of any nominal size as well as for motorized valves. The tightness test is carried out with the valves installed in TC 3.

Technical Documentation

TC1, TC2, TC3 Valve Proving System Technical Documentation