High Pressure Slurry Valve

2" - 24" (DN50 - DN600)

Class 300 - 900 (up to 100-150 bar depending on size)

ASME B16.34, manufacturer-specific high-pressure slurry design

A216 WCB, A217 WC6/WC9, A182 F316, A182 F51/F53

Metal-to-metal (Stellite 6 overlay on both seat and gate tip), reinforced elastomer inserts available for lower-pressure configurations within the range

Heavy-wall one-piece or two-piece bolted body, pressure seal bonnet above Class 600, full-port bore with abrasion-resistant internal geometry, rising stem OS&Y or pneumatic/hydraulic actuated

When Your Slurry Line Runs at 100 Bar

Standard slurry valves stop at Class 150 or 300. That covers most tailings transport, most mineral processing circuits, most applications where "slurry valve" means something that handles abrasive media at moderate pressure. But some lines run harder. Mineral processing high-pressure pump discharge lines push 50-100 bar. Dense media separation circuits operate at pressures where a standard slurry valve body wall would be too thin — not just for the pressure rating, but for the combined attack of pressure and abrasion.

At those pressures, slurry velocity through the seat area accelerates. The same abrasive particles that wear out a Class 150 seat in a year will cut through an unprotected metal seat in weeks at Class 900 flow velocities. This is why high pressure slurry valves get Stellite 6 overlay on both the seat face and the gate tip — two surfaces that see the highest velocity and the most direct particle impact. Stellite 6 is hard. It resists erosion at velocities that would strip soft metal in a single shift.

The Body Is Built for Two Enemies at Once

Pressure and abrasion attack different parts of the valve. Pressure stresses the body walls, the bonnet connection, every bolt and every gasket. Abrasion attacks the internal flow surfaces — the seat area, the gate edges, the body cavity walls where slurry recirculates. A high pressure slurry valve has to fight both at the same time, and that means substantially heavier wall thickness than a standard slurry valve at the same nominal size.

You can see the difference if you stand a 6" Class 900 slurry valve next to a 6" Class 150 slurry valve. The Class 900 body is visibly thicker, visibly heavier. The internal geometry — flow passages, seat pocket, gate channel — is designed to minimize turbulence zones where abrasive particles accelerate and concentrate. Smooth transitions, generous radii, no sharp internal corners where slurry can stall and erode.

Pressure Seal Bonnet Above Class 600

Bolted bonnets with gaskets work fine up to Class 600. Above that, the bonnet gasket becomes a liability — internal pressure pushes against it constantly, and under slurry service conditions the gasket degrades faster than in clean fluid applications. Pressure seal bonnets solve this by using internal pressure to energize the seal. As line pressure increases, the seal gets tighter. There's no bonnet gasket to replace, no bolt tension to maintain against creep. The higher the pressure, the better the bonnet seal.

For Class 300-600 applications within the high-pressure range, bolted bonnets remain standard — simpler to maintain, well-proven, and the gasket loads are manageable. But if you're running Class 900 slurry, you want a pressure seal bonnet. It's not a premium option — it's the correct engineering choice.

Material Selection Matches the Service

A216 WCB covers most applications — carbon steel, cost-effective, proven in mining slurry at elevated pressures. A217 WC6/WC9 for higher temperature service. A182 F316 for corrosive slurry chemistry — acidic process water, chloride-rich tailings. A182 F51/F53 duplex stainless for applications where you need both corrosion resistance and mechanical strength at pressure. The material choice depends on what's in your slurry and what temperature it runs at, not just the pressure class.

A: You can — for about three months. Standard gate valves aren't designed for abrasive media. The seating surfaces, body internals, and stem packing degrade rapidly when slurry flows through them. A high pressure slurry valve has Stellite overlay seats, abrasion-resistant internal geometry, and packing designed for particulate-laden fluid. The pressure rating is similar, but the slurry capability is fundamentally different.

A: Reinforced elastomer inserts can handle Class 300-400 in some configurations, but above Class 600 the pressure and velocity are too high for elastomer to maintain seal integrity against abrasive slurry. Metal-to-metal with Stellite overlay is the standard seat above Class 600.

A: You can, but it's not necessary and adds cost. Bolted bonnet gaskets are manageable at Class 300. Pressure seal bonnets become the recommended — and in many cases required — option above Class 600 where bolted gasket loads become impractical to maintain.

A: 2" through 12" are the most common. Above 12" at Class 900, the body weight, wall thickness, and actuation force requirements become very large. 16" and 24" Class 900 slurry valves exist but are special-order items with long lead times.

A: Yes — and for Class 600 and above, hydraulic actuation is often the practical choice. The seating forces required at high pressure exceed what pneumatic cylinders can deliver economically. Hydraulic actuators provide controlled, high-force operation without the air consumption issues of large pneumatic cylinders.