Standard Integral Air Valve Safety High Performance With Epoxy Coating

Working Pressure:16kg/cm²
Shell Test Pressure:24kg/cm²
Seat Test Pressure:18kg/cm² 
Media:Water,Neutral Oil
Working Temperature:0-52°C

100％ Fusion Bonded Epoxy Coating for Inner and Outside Surface

Flange Drilled According to EN1092 PN10,PN16

Size:DN50--DN100

Standard Means Proven — The 4004T Integral Air Valve for Everyday Pipeline Air Management

In valve engineering, "standard" is a word that carries weight. It means the design has been specified, installed, operated, and proven across thousands of projects. It means the failure modes are understood, the maintenance procedures are documented, and the spare parts are available. It means every water utility engineer, every EPC piping designer, and every installation contractor knows exactly what to expect. The Model 4004T is Huaze's standard integral air valve — a dual-function combination air/air-vacuum valve with an integrated one-piece body design, PN16 rated, DN50–DN100, flanged to EN1092 PN10/PN16. It combines continuous automatic air release during pipeline operation with high-volume air discharge during filling and air intake during draining — all housed in a single integral ductile iron body with fewer joints, fewer leak paths, and simpler on-site handling than a multi-piece design. The 4004T is the valve you specify when you need proven, reliable dual-function air management without the cost or complexity premium of a larger or more specialised valve — the standard choice that gets the job done, safely and with high performance, year after year.

Product Overview

The Model 4004T is a flanged integral air valve — also called a combination air valve — combining two fully automatic float-operated functions in one integrated ductile iron body. The small-orifice float continuously vents air that accumulates at pipeline high points during normal pressurised operation — preventing flow restriction, pumping energy waste, and air-related water hammer. The large-orifice float provides bulk air management: it expels large volumes of air during pipeline filling (commissioning or restart), enabling fast fill at the pump's design rate; and it admits atmospheric air during pipeline draining or pressure loss, preventing the vacuum collapse that kills pipelines. Both floats are solid-welded stainless steel 304 — corrosion-proof, permanently buoyant, incapable of water-logging. The integral body is cast from EN-GJS-500-7 (GGG50) ductile iron and receives 100% internal and external fusion bonded epoxy coating at 250 um DFT, spark-tested at 3 kV. Every 4004T is shell-tested at 24 bar, seat-tested at 18 bar (both orifices independently), and verified for full dual-float operation before dispatch. Manufactured by Shandong Huaze Valve Co., Ltd. (ISO 9001, since 1998), the 4004T operates fully automatically on buoyancy alone — no electricity, no control signal, no compressed air, no operator.