Air release valve delivery information

Forty DN80 Double Orifice Air Valves in One Run

Repeating one size forty times is its own kind of test. A mixed order stresses the workshop's range; a single-size run stresses its consistency. The batch that left the factory on November 10 was the second kind: 40 double orifice air release valves, every one of them DN80.

The order: 40 pcs DN80, PN16, flanged to EN 1092-2, bodies cast in GGG50 ductile iron. The size and the pressure class are cast into the metal beside the flange, so no label is needed to read them. For the buyer this is a single line item on one purchase order. Inside the workshop it is forty castings that have to cool, clean, machine and seal the same way, forty times in a row.

DN80 sits in the middle of the range and carries a middle-sized load. At 16 bar the flange on this batch sees around 8 kN of end thrust, roughly a sixth of what a DN200 carries and about four times a DN40. The parts that manage that load follow the same logic. The float must be buoyant enough to seat against line pressure, and the seat must hold it. On this size both parts are compact enough to finish in one machining pass, which is exactly where a long run pays off: by the tenth casting the fixtures are dialled in, and by the fortieth the dimensions repeat.

The double orifice layout is the same as on every valve we ship. Under the hood, the large orifice vents the main at full bore during filling and lets air back in on drain-down, so the pipe is not pulled flat. In the side chamber, the small orifice releases the air that keeps coming out of solution while the line runs under pressure. The small float reads the water level in its chamber, and it works by the same logic in valve number one and valve number forty.

Every body is cast in GGG50 ductile iron to ISO 1083 and EN 1563, epoxy coated inside and out, and pressure tested before packing. Each nameplate lists the body material and the seal; the month of manufacture is cast into the body itself, 202611 on this batch.

Forty valves pack into four wooden cases, ten per case, each valve held in its own cardboard grid cell so nothing touches in transit. The plastic plugs on the side outlets stay on until installation.

One size, forty units, four cases, one shipment. Repeat orders of a proven size are the simplest way to judge a factory: the valve has to come out exactly what the first order was.