Conforms to ISO 5752 Series 20 and API 609 Table 1 short dimensions, saving valuable footprint in compact OEM machinery, mobile skids, and shipboard manifolds.

On concentric resilient models, the molded elastomeric liner wraps around the body faces, forming a perfect seal against mating pipe flanges without extra flat gaskets.

Engineered locating holes or slotted centering lugs accommodate ASME Class 150, EN 1092-1 PN10/PN16, and JIS 10K flanges without modifying body castings.

Direct-coupled pneumatic rack-and-pinion actuators cycle in 0.3 to 0.8 seconds under 0.4–0.7 MPa plant shop air, delivering instantaneous automated flow shutoff.

Weighing up to 50% less than flanged or lugged valves, the wafer design eliminates pipe sagging and reduces the need for expensive structural pipe hangers.

Precision CNC-machined ISO 5211 top works allow direct pneumatic actuator assembly without external brackets, eliminating backlash and extending stem packing life.

Q1: How do wafer butterfly valves seal against pipeline flanges without separate gaskets?

On concentric rubber-lined wafer valves, the elastomeric seat liner wraps around the body sealing faces, extending slightly beyond the metal shell. When bolted between mating pipe flanges, the liner compresses directly against the raised or flat pipe faces, forming an airtight and watertight seal without requiring separate flat sheet gaskets.

Q2: What is the primary difference between wafer and lugged valves during plant maintenance?

Wafer valves are clamped between two companion flanges with through-bolts spanning the entire valve body. If one flange is unbolted, the valve loses compression and cannot hold pressure. If your maintenance plan requires dead-end service (dismantling downstream piping while keeping upstream piping pressurized), a lugged or double-flanged valve must be selected.

Q3: How do universal alignment holes ensure accurate flange centering?

Delco wafer valves feature molded-in locating ears or slotted bolt guides that closely hug the outer diameter of standard flange bolts. During field assembly, the through-bolts pass snugly through these centering ears, guaranteeing that the valve disc and bore are concentric with the pipeline I.D. to prevent disc-edge impingement on pipe walls.

Q4: What precautions are needed when clamping wafer valves between plastic or lined pipes?

When installing wafer butterfly valves between thermoplastic (UPVC/CPVC) or PTFE-lined pipe flanges, operators must follow cross-pattern torque procedures using calibrated torque wrenches. Excessive bolt torque can deform plastic stub-end flanges or pinch the valve liner, causing elevated operating torque or premature disc seal wear.