Gate valves to GOST 5762-2002 for PN up to 250: cast iron or steel body, rigid or flexible wedge, rising or non-rising stem. Seat tightness is governed by GOST 9544-2015: class A means no visible leakage, classes B and C allow a rated leakage and suit water and heating service. The class is stated in the specification because it drives both the price and the suitability for a given medium.
Every valve is hydrotested for body strength and seat tightness; the report with actual values ships with the lot. The wedge is left partly open for transport so the seating surfaces are not deformed, and the flanges are blanked. Face-to-face length follows the agreed standard or drawing.
