4 in. Ductile Iron Double-Door Wafer Check Valve — Midland Catalog-Designated UL 312 / ULC
4 in. Ductile Iron Double-Door Wafer Check Valve — Midland Catalog-Designated UL 312 / ULC
✓ In stock at the manufacturer — typically ships within 1–2 business days.
Freight item — ships LTL (Lower 48)- Flat-rate freight: $199 per order
- Freight orders of $5,000 or more ship free
Buying several, or need a liftgate or jobsite delivery? Request an exact freight quote — usually answered the same business day.
The 4 in. ductile iron double-door wafer check valve (part 963004UL) has two half-disc doors in 316 stainless steel and an EPDM seat inside a thin wafer body that mounts between two pipe flanges. Midland's catalog designates this model UL 312/ULC; Apex has not independently confirmed the listing record. If your project requires listing documentation, ask us and we will request the current documentation from Midland before you order.
Technical Specifications
| Manufacturer Part Number (MPN) | 963004UL |
| Nominal Size | 4 in. |
| Valve Type | Double-door (dual-plate) wafer check valve |
| Flange fit | ASME B16.1 Class 125 and ASME B16.5 Class 150 flanges, per Midland's catalog |
| Catalog designation | UL 312/ULC, per Midland's catalog. Listing documentation on request |
| Pressure rating | 300 psi (Midland product page). Ask us for the temperature rating |
| Coating | Fusion-bonded epoxy, interior and exterior, to AWWA C550 (Midland catalog) |
Dimensions
| Inlet-to-outlet length | 3.66 in. |
| Opening size | 5.35 in. |
Materials of Construction
| Body | Ductile iron |
| Doors (discs) | Stainless steel, AISI 316 |
| Seat | EPDM |
| Seal | PTFE |
Materials and dimensions are from Midland's product page for 963004UL. Ask us for any value not shown.
Installation
Install between two pipe flanges with the flow arrow pointing downstream, and follow the manufacturer's installation instructions.
Other Sizes in This Series
| Size | Part # |
| 4 in. catalog-designated UL 312/ULC (this page) | 963004UL |
| 6 in. catalog-designated UL 312/ULC | 963006UL |
The standard version of this size, part 963004, has aluminum bronze doors and a shorter body. Ask us if you want to compare the two.
Cross-References & Interchange
Replacing another brand's 4 in. dual-plate wafer check? Send us the part number and flange class and we will check the fit with Midland before you order.