Camlock Fittings Guide: Types A Through DP, Explained
Camlock — cam-and-groove — couplings let you connect and disconnect large-bore lines by hand, no wrenches, no threads to cross: a quarter-turn of two lever arms locks the joint or breaks it. That's why every tanker offload, IBC tote transfer, chemical feed line, and irrigation mainline crew reaches for camlocks instead of threaded pipe. The trade-off for that speed is a type-letter system that trips up a lot of first-time buyers — A, B, C, D, E, F, DC, DP aren't sizes or materials, they're connection types, and ordering the wrong letter is the single most common camlock mistake we see at the quote desk. This guide explains what each letter actually means, how the two halves mate, why same-size parts from different brands generally fit together, and links each type to its live 316 stainless products and filtered view of the collection.
Buying Summary — What You Need, By Situation
| I need to… | Get this | Why |
|---|---|---|
| Connect a hose to a pipe with male external threads | Type C on the hose + Type A on the pipe | Type A's female NPT threads onto the male pipe end |
| Connect a hose to a tank or valve port with female internal threads | Type C on the hose + Type F on the port | Type F's male NPT threads into the female port |
| Join two hose ends together | Type C on one hose + Type E on the other | One coupler half, one adapter half — that's all a joint needs |
| Connect two straight pipe runs, both male-threaded | Type A on one pipe + Type D on the other | Both ends thread onto male pipe; the camlock halves mate to each other |
| Protect an open male adapter when the line's disconnected | Type DC dust cap | Caps the adapter's groove ring so grit stays off the sealing face |
| Protect an open female coupler when the line's disconnected | Type DP dust plug | Plugs the coupler so grit stays off the lever mechanism and seal |
The Two Halves: Coupler vs. Adapter
Every camlock size has two mating halves. The coupler carries the two lever arms — that's the piece people picture when they hear "camlock." The adapter carries the raised groove ring the arms lock onto. Any coupler mates with any adapter of the same nominal size, regardless of type letter or manufacturer, because both halves are cut to the same common coupling profile — more on that below.
What actually changes between the type letters isn't the camlock end at all — it's the other end: a female NPT thread, a male NPT thread, or a barbed hose shank. So the whole system reduces to two decisions: pick your camlock half (coupler if you want the lever arms, adapter if you want the groove ring), and pick the other-end connection to match whatever you're attaching to. Type DC and DP aren't couplings at all — the DC dust cap fits over an open male adapter and the DP dust plug fits into an open female coupler, keeping contaminants off the sealing face between hookups.
Type A — Male Adapter, Female NPT
Adapter half (groove ring, no lever arms) with a female NPT thread on the back end — screws onto a male-threaded pipe nipple, valve outlet, or pump discharge. Mates with any B, C, or D coupler.
Type B — Female Coupler, Male NPT
Coupler half (the two lever arms) with a male NPT thread — threads into a female-threaded port on a tank, manifold, or pump. Mates with any A, E, or F adapter.
Type C — Female Coupler, Hose Shank
The one you'll use on the most hose ends: coupler half plus a barbed shank for a hose clamp. Mates with any A, E, or F adapter.
Type D — Female Coupler, Female NPT
Coupler half plus a female NPT thread — screws onto a male-threaded pipe stub. Mates with any A, E, or F adapter.
Type E — Male Adapter, Hose Shank
Adapter half plus a barbed hose shank — the piece that lets two hose ends connect to each other through a Type C coupler.
Type F — Male Adapter, Male NPT
Adapter half plus a male NPT thread — threads into a female-threaded port.
Type DC — Dust Cap
Protects an open male adapter (A, E, or F) when the line is disconnected — caps the adapter's groove ring so grit and debris stay off the sealing face and the next hookup seals clean.
Type DP — Dust Plug
Protects an open female coupler (B, C, or D) when the line is disconnected — same job as the DC cap, sized to plug the coupler instead of capping the adapter.
Why Different Brands Interchange
Cam-and-groove couplers and adapters share a common coupling-and-groove profile at each nominal size, so a coupler from one maker generally locks onto an adapter from another at the same size. The type-letter designations (A through F, DC, DP) are consistent across the industry for the same reason. Midland describes its cam-and-groove fittings as interchangeable with most market systems. Confirm the fitting type, nominal size, gasket, and compatibility with the existing system before ordering.
Quick Reference — All Eight Types
| Type | Camlock half | Other end | Mates with |
|---|---|---|---|
| A | Adapter | Female NPT | Any B/C/D coupler |
| B | Coupler | Male NPT | Any A/E/F adapter |
| C | Coupler | Hose shank | Any A/E/F adapter |
| D | Coupler | Female NPT | Any A/E/F adapter |
| E | Adapter | Hose shank | Any B/C/D coupler |
| F | Adapter | Male NPT | Any B/C/D coupler |
| DC | Dust cap | — | Fits any open male adapter (A/E/F) |
| DP | Dust plug | — | Fits any open female coupler (B/C/D) |
Sizing and Material — Two More Decisions
Picking the type letter only answers "what does each end connect to." You still need to confirm the actual nominal size matches your hose or pipe — a "2 in." camlock is a label, not a caliper reading, and the two sizes never lock together even when forced. See Camlock Sizing: Why Camlock Size Isn't Hose ID for how to check that before you order. And the body material — aluminum, polypropylene, or stainless — changes which chemicals and services the fitting can handle; see Camlock Materials: Aluminum vs Polypropylene vs Stainless. Every camlock joint also depends on the gasket inside the coupler doing the actual sealing — covered separately in Camlock Gaskets: Buna-N vs Viton.
Frequently Asked Questions
What's the difference between a camlock coupler and an adapter?
The coupler carries the two lever arms that lock the joint. The adapter carries the raised groove ring the arms lock onto. You always need one of each to make a connection — never two couplers or two adapters together.
Do all camlock brands interchange?
Within the same nominal size, same-size couplers and adapters built to the common cam-and-groove profile generally mate across brands. Midland describes its cam-and-groove fittings as interchangeable with most market systems; confirm the fitting type, nominal size, gasket, and compatibility with your existing fittings before ordering.
Which type do I need to connect a hose to a threaded valve outlet?
Put a Type C coupler on the hose end. On the valve outlet, use a Type A adapter if the outlet has male external threads, or a Type F adapter if the outlet has female internal threads.
What's the difference between a DC dust cap and a DP dust plug?
A DC dust cap fits over an open male adapter (the groove-ring half). A DP dust plug fits into an open female coupler (the lever-arm half). They're not interchangeable with each other — match the cap or plug to whichever half is sitting open.
Related Guides
- Camlock Sizing: Why Camlock Size Isn't Hose ID
- Camlock Materials: Aluminum vs Polypropylene vs Stainless
- Camlock Gaskets: Buna-N vs Viton
- Hose Barb Sizing Chart
- Irrigation & Agriculture Fittings and Valves
- Water Treatment & Chemical Feed Supplies
Type-letter definitions and the coupler/adapter interchange principle are standard, widely published cam-and-groove reference information. Confirm the exact size and material against the product page before ordering, and ask us before specifying for a chemical service outside plain water or general transfer.
Send us what's on each end of the connection — hose, pipe thread, or tank port — and what's running through it. Request a quote and you'll have the right part numbers confirmed by a person the same business day.
Technical data disclaimer: Specifications, dimensions, pressure/temperature ratings, and compatibility information on this page are compiled from manufacturer publications and are provided for reference only. Always verify suitability for your application against the manufacturer’s current documentation before purchase or installation. Apex Flow Solutions assumes no liability for errors, omissions, or misapplication of this information.