Stop valve

Blocking valves

Blocking valves KZ (КЗ)

Blocking valves are used as locking device in pipe lines transporting liquids and fluids. They provide line shutdown only in one direction – “under slide valve” (downstream direction).


  • Parts of blocking unit are made of stainless, highly wear resistant steels:

          o 30X13 — spindle;

          o 20X13 — seat.

  • Forged valve body is made of:

          o alloy steel 18HGT (18ХГT) for non-aggressive media (water, steam, air, natural gas, nitrogen, inert gases, fuel oil, oils, diesel fuel, petroleum and petroleum products);

          o cold-resistant steel 09G2С (09Г2С);

          o stainless steel 12H18N10T (12Х18Н10T) for food and aggressive media (drinking water, liquid food products, alcohol, acids, alkalis, natural gas).

Parts, made of austenitic steel, are checked on intergranular corrosion resistance according to GOST 6032-75.


  • Climatic modification: operations in moderate and cold environment - UHL1 (УХЛ1), operations in cold environment - HL1 (ХЛ1) GOST 15150-60;
  • Nominal pressure:  1,6 (16), 4(40), 6,3(63), 16(160) MPa (kgf/cm2);
  • Ambient temperature: -60°Cto +40°C;
  • Working medium temperature: up to ± 450°С;
  • Latch mechanism leak resistance: class A GOST 9544-2005;
  • ATBF (average time between failures): 1000 cycles;
  • Average life: not less 12 years;
  • Total service average life: not less 1500 cycles;
  • Operation: manual;
  • Warranty (from the first day of commissioning): 12 months;
  • Manufactured and delivered per: TU 3742-152-075-38145-2006.