Zero Spill Quick Connect Set, 3/4" FNPT, Water and Glycol
ABOUT THIS PART
A zero spill quick connect coupling set for 3/4 inch water and glycol lines, built to N.B. Oler specification and not sold by anyone else. One male half, one female half, 3/4 inch female NPT on the back of both. $137.50 the pair.
Nobody catalogs this size
Flat face no-spill couplings stop at 1/2 inch everywhere we could buy from. We needed 3/4 for hot water and glycol lines, so we had these made with our own gold N.B. Oler marking on the body.
On a heating loop the coupling is usually the tightest restriction in the circuit. Stepping a 3/4 inch line down to a 1/2 inch coupling costs you heat transfer at the jacket, every hour it runs.
Water and water glycol only
The seals are EPDM, which is the right elastomer for water and glycol and the wrong one for hydrocarbons. These do not go on a solvent line. They are not a coolant or chiller fitting either. A chiller or glycol loop running colder than -20 C (-4 F) is outside the rating. These belong on the hot water side.
Specifications
| Price | $137.50 the pair, which buys both halves |
| Set contents | One male half, one female half |
| Connection, each half | 3/4 in FNPT |
| Maximum working pressure | 113.8 psi (7.8 bar) at 25 C (77 F) |
| Temperature range | -20 C to 80 C (-4 F to 176 F) |
| Freezing | The fluid must not be allowed to freeze inside the coupling |
| Seal material | EPDM |
| Body | Nickel plated brass, black paint, gold N.B. Oler marking |
| Fluid released on disconnect | About 0.2 ml at up to 7 psi (0.5 bar) |
| Serviceability | Not rebuildable, no rebuild kit or spare seals |
| Sizes stocked | 3/4 in |
| Sizes available to order | 1/4 in and 1/2 in, NPT or push barb |
The 0.2 ml figure, with its condition
Both halves close as they separate, so roughly 0.2 ml is released instead of a line's worth onto the floor. That 0.2 ml holds up to 7 psi (0.5 bar). Break the line above that and more comes off, so vent the loop first when you can.
Not rebuildable
There is no rebuild kit and no spare seals for these. When a coupling is worn out it gets replaced, not serviced. Keep a spare set on the shelf if the loop cannot be down.
SPECIFICATIONS
▦ IN YOUR MANUAL
This part appears in the operator manual that ships with your system. The QR code there links to this page.
◈ REFERENCE FOR THIS PART
COMMON QUESTIONS
What do I actually get for the price?
Both halves, one male and one female, for $137.50. Each has a 3/4 inch female NPT port on the back.
Can I use these on a solvent line?
No. The seals are EPDM, which swells in hydrocarbons. These are for water and water glycol only. Putting them on a butane or propane line will fail the seal.
What pressure are they good for?
113.8 psi (7.8 bar) at 25 C (77 F).
What temperature can they take?
-20 C to 80 C, which is -4 F to 176 F. The fluid must never freeze inside the coupling.
How much fluid comes out when I disconnect?
About 0.2 ml at up to 7 psi (0.5 bar). Above that more is released, so vent the loop before you break it if you can.
Can I run these on my chiller or a coolant loop?
No. These are hot side only. A chiller or glycol loop running colder than -20 C (-4 F) is outside the rating.
Why can I not find this size anywhere else?
Because nobody catalogs a 3/4 inch flat face no-spill coupling. We had these built to our specification. Every other flat face no-spill stops at 1/2 inch.
Can they be rebuilt?
No. There is no rebuild kit and no spare seals. When a coupling is done, it is replaced.
Do you make other sizes?
1/4 inch and 1/2 inch can be ordered, in NPT or push barb. Only the 3/4 inch is stocked.
Why no-spill instead of a plain quick connect?
A standard quick connect dumps whatever is in the coupling the moment you break it, and hot glycol on the floor is a burn. A flat face closes both halves as they separate, so the line stays in the line and no air is pulled into the loop when you couple back up.