whole unit is slurry valve

2" - 36" (DN50 - DN900)

Class 150 - 300 (up to 20-50 bar)

Manufacturer-specific, ASME B16.34 body rating

A216 WCB, ductile iron (A536 65-45-12), A351 CF8M

Metal-to-metal (Stellite 6 overlay), or replaceable elastomer seat insert

One-piece cast body (no bolted body split), full-port bore, integrated seat pocket, heavy wall construction, gate with guiding ribs, OS&Y or pneumatic actuated

One Body, No Body Gasket — That's the Whole Idea

Most slurry valves come in two pieces. Two halves bolted together. A gasket sandwiched between them. That gasket sits right in the wetted zone — abrasive slurry flows over it, under it, through every microscopic gap that opens up after a thousand thermal cycles. The joint leaks. It always leaks eventually. Mines tell us the same story: they tighten the body bolts, replace the gasket, six months later it's leaking again because the slurry has been eating the gasket edge from inside the flow path.

A whole unit slurry valve doesn't have that joint. The body is a single casting — one piece, no split, no body gasket, no body bolts to maintain. You still have the bonnet-to-body connection, but that gasket sits above the wetted zone where slurry never touches it. The leak path that causes the most trouble on two-piece valves simply doesn't exist here.

That's the reason mines running 24/7 tailings lines specify whole unit valves. Fewer leak paths mean fewer shutdowns. In abrasive service, every joint is a liability. Remove the joint, remove the liability.

What You Give Up — and Why It's Worth It

A one-piece body means you can't split the valve open to inspect internals from the side. You go through the bonnet opening — remove the bonnet, pull the gate and seat up from the top. For most maintenance crews that's actually faster than unbolting a two-piece body, realigning it, and re-gasketing it. But if you need visual access to the body cavity without pulling the bonnet assembly, a two-piece design gives you that option.

The tradeoff is straightforward. You lose side-access inspection. You gain zero body-joint leaks. In continuous slurry service where shutdowns cost production hours, that tradeoff favors the whole unit valve almost every time.

The Gate and Seat Work Together

The gate runs on guiding ribs cast into the body — not loose guides that can shift under pressure. Full-port bore means no flow restriction when the valve is open, which keeps slurry velocity smooth and reduces turbulence-induced wear on the body walls. The seat pocket is integrated into the casting, so there's no separate seat ring gap for slurry to infiltrate.

For metal-to-metal seating, Stellite 6 overlay on the seat face handles abrasive wear. For applications where tighter shutoff matters more than maximum wear resistance — lower-pressure water-slurry mixtures, for example — a replaceable elastomer seat insert gives you bubble-tight closure and the option to swap the seat without replacing the entire seating surface.

Heavy Walls Because Slurry Doesn't Care About Your Schedule

Abrasive slurry erodes everything it touches. A thin-wall body might meet the pressure rating on paper, but after two years of tailings flowing through it at 3-4 m/s, the internal surfaces are worn thin in exactly the spots where the flow turns or accelerates. Whole unit valves are cast with heavy walls — extra thickness where experience shows wear concentrates. That's not over-engineering. That's mining experience built into the casting.

A: Yes. Remove the bonnet, pull the gate, and access the seat pocket from the top. The seat insert or overlay is serviced through the bonnet opening — no need to unbolt the valve from the pipeline.

A: You can, and many plants do. But in abrasive slurry service, the body gasket sits in the flow path and gets attacked from inside the line. Re-gasketing a two-piece body means a full shutdown, unbolting, realigning, and reassembling. A whole unit valve eliminates that leak path entirely.

A: Up to 36" (DN900). Beyond that, casting a one-piece body becomes impractical — wall thickness, weight, and foundry capability push you toward a two-piece design at larger sizes.

A: The casting is more expensive because it's larger and heavier as a single piece. But you eliminate the body gasket, body bolts, and the maintenance labor associated with that joint. Over the valve's service life, the total cost is typically lower in abrasive slurry applications.

A: No. The bonnet-to-body gasket sits above the wetted zone — slurry doesn't flow across it. It's a standard pressure gasket in a clean, dry connection. Nothing like the body gasket on a two-piece valve that sits directly in the slurry flow path.