FIELD: manufacture of fittings; supply of compressed air pulses to vertical elements of bag filter in filtration station for cleaning contaminated gases. SUBSTANCE: valve gear housing has chamber. Control valve closes chamber outlet in closed position and opens it in open position. Shut-off member of main valve is made in form of piston and is located for free motion in inlet circular cylindrical portion of housing. Valve chamber inlet is formed by circular clearance between surfaces of piston and housing. Length of circular cylindrical portion of housing is sufficient for embracing at least larger portion of piston in closed position. EFFECT: enhanced reliability. 3 cl, 2 dwg
