Double-door wafer check valves have two half-disc doors inside a thin ductile iron body that mounts between two pipe flanges. Apex Flow Solutions carries Midland 963-series models, including two that Midland's catalog designates UL 312/ULC. Filter by size, or request a quote.
View all wafer check valves (11)Need flange-class confirmation or a project quote?Search by part number
Related check valves
All wafer check valves
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2 in. Ductile Iron Double Door Wafer Check Valve -
2-1/2 in. Ductile Iron Double Door Wafer Check Valve -
3 in. Ductile Iron Double Door Wafer Check Valve -
4 in. Ductile Iron Double Door Wafer Check Valve -
4 in. Ductile Iron Double-Door Wafer Check Valve — Midland Catalog-Designated UL 312 / ULC -
5 in. Ductile Iron Double Door Wafer Check Valve -
6 in. Ductile Iron Double Door Wafer Check Valve -
6 in. Ductile Iron Double-Door Wafer Check Valve — Midland Catalog-Designated UL 312 / ULC -
8 in. Ductile Iron Double Door Wafer Check Valve -
10 in. Ductile Iron Double Door Wafer Check Valve -
16 in. Ductile Iron Double Door Wafer Check Valve
Construction
| Part | Standard Midland 963-series models carried by Apex | Catalog-designated UL 312/ULC models (963004UL, 963006UL) |
|---|---|---|
| Body | Ductile iron | Ductile iron |
| Doors (discs) | C954 aluminum bronze | 316 stainless steel |
| Seat | EPDM | EPDM |
| Seal | PTFE | PTFE |
| Finish | Fusion-bonded epoxy, per Midland's sell sheet | Fusion-bonded epoxy |
Materials are from Midland's product pages for each part number. Midland's ductile iron wafer check valve spec sheet (PDF) shows the materials list and dimensions for the standard models.
Pressure ratings
Midland's product pages rate 963004UL and 963006UL at 300 psi. Midland's current series sell sheet states a 300 psi working pressure. Confirm the rating for the specific size before specifying the valve.
About the catalog-designated UL 312/ULC models
Midland's catalog designates 963004UL and 963006UL as UL 312/ULC models. 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.
Installing a wafer check valve
The wafer body centers between two pipe flanges and is held by the flange bolts. Midland's catalog states that 963004UL and 963006UL fit ASME B16.1 Class 125 and ASME B16.5 Class 150 flanges, and Midland's sell sheet states that the standard series installs between Class 125 flanges. Follow the manufacturer's installation instructions.
Compliance note
No lead-free, potable-water or NSF certification has been confirmed for this series. Midland provides a California Proposition 65 warning that names lead.
Common questions
What sizes do you carry?
Standard models in 2, 2-1/2, 3, 4, 5, 6, 8, 10 and 16 in., and the two catalog-designated UL 312/ULC models in 4 and 6 in. Midland also catalogs 12 and 14 in., which we do not carry.
What is the difference between the standard and catalog-designated models?
The door material, the body length and the documentation. 963004UL and 963006UL use 316 stainless steel doors, Midland lists a longer body for them than for the standard 4 in. and 6 in. models, and they appear in Midland's catalog section for its UL-designated models. Confirm the length before swapping one for the other, and ask us if you need the documentation.
Can you quote freight for larger sizes?
Yes. Send the size, flange class and quantity through Request a Quote.