9620-Series Spring Kits: Which Kit Fits Which Valve

If a 9620-series swing check is leaking back, slamming, or just due for service after years in the field, the question that actually needs answering is simple: is this a kit job, or a whole-valve job? Here's the complete size-to-kit cross-reference for our AWWA C508 swing check line, what tends to wear first, and how to decide which repair path fits your situation.

Size-to-Kit Cross-Reference

Each kit is a genuine Midland Industries replacement part built for the matching valve size — the 96203SK fits the 3 in. valve family (flanged, lever & weight, and UL/FM configurations), and so on through the line. If you're not certain which configuration you have in the field, send us the nameplate or a photo and we'll confirm the correct kit before you order.

Note the 12 in. kit is stocked even though a 12 in. flanged base valve isn't currently listed in our catalog — that's not an error. Plenty of 12 in. 9620-series valves are already installed in the field, and the kit exists to service them; if you need a new 12 in. base valve, ask us and we'll source it.

What Wears First

Swing check valves fail in fairly predictable order, and it's the same pattern regardless of manufacturer:

• The seat and disc-to-seat contact. This is the surface that closes on every single cycle, so it's the most frequent point of wear — a worn or pitted seat is the most common cause of a valve that leaks back when it should be holding tight.
• The hinge pin and bushing. Wear here lets the disc drift out of alignment with the seat, which compounds the leak-back problem even if the seat itself is still in reasonable shape.
• The spring, where the valve uses one. A spring that's lost tension over years of cycling closes more slowly, which raises the risk of slam-related water hammer even if the valve still technically seals.

A spring kit is built to address these internal wear components. For the full mechanism, see our Swing Check Valve Guide; for what slam actually does to a system and how to prevent it, see Check Valve Orientation & Installation.

Kit vs. Whole-Valve Replacement — the Decision

A kit is the right call when:

• The body and flange faces are sound — no corrosion, no pitting, no cracked or damaged bolt holes.
• The symptom is leak-back, chatter, or slam rather than a physically compromised body.
• Getting the line back in service quickly matters more than a full teardown-and-inspection cycle.
• The kit cost, plus labor, comes in well under the cost of a new valve plus freight and installation downtime.

Whole-valve replacement is the right call when:

• The body itself shows corrosion, pitting, or flange damage that a kit won't fix.
• Requirements changed since the original install — for example, the application now needs a UL/FM listed valve and the installed unit is a plain flanged AWWA C508 valve.
• The valve has already been rebuilt more than once and the body is due for retirement regardless of kit availability.
• Freight-inclusive new-valve pricing comes in close enough to the kit-plus-labor cost that the fresh body and full warranty are worth the difference.

If you're not sure which side of that line your valve falls on, send us the nameplate, the size, and a photo of the body condition — that's usually enough for us to point you the right direction before you commit to either path.

Frequently Asked Questions

How do I know which spring kit fits my valve?

Match the nominal size on the valve's nameplate to the size-to-kit table above — a 3 in. valve takes the 96203SK, a 6 in. valve takes the 96206SK, and so on. If the nameplate is worn or you're not sure of the size, send us a photo and we'll confirm the correct kit.

Can I rebuild a UL/FM listed valve with a standard kit and keep the listing?

Don't assume yes without checking. Fire-protection listed valves can have listing requirements tied to specific certified repair parts, and using a non-certified kit can jeopardize that listing. If your valve is UL Listed / FM Approved, tell us before you order a kit so we can confirm the correct part maintains the certification.

Is a 12 in. spring kit available even though the 12 in. flanged valve isn't listed?

Yes — the 962012SK is stocked to service 12 in. valves already installed in the field, even though a new 12 in. flanged base valve isn't currently in our standard catalog. If you need a new 12 in. valve, ask us and we'll source it.

What if my valve is a different brand?

Send us the nameplate, size, and configuration and we'll confirm whether a 9620-series kit is a match or whether you need a different part. Swing check internals vary enough between manufacturers that this is worth confirming before ordering.

Related Guides

• Swing Check Valve Guide
• Check Valve Types Compared
• Check Valve Orientation & Installation
• Y Strainer vs. Basket Strainer
• Buna vs. Viton Check Valve Seats
• Strainer Mesh & Sizing Reference

Published performance data is general engineering reference, not a certification for your application. Confirm specifics against the manufacturer datasheet or ask us.

Written by the Apex Flow Solutions technical desk — twenty years of industrial distribution experience behind every guide.