Overview
The Parker 5500 Series is a self-sealing brass quick-disconnect coupling designed for field-serviceable and modular refrigeration systems. This listing provides a matched male/female pair — a 5502 male coupling half and a 5505 female coupling half — each with a 1/4" ODF (outside diameter flared) copper sweat connection on a 3/8" (-06) coupling body. When threaded together, the pair opens a sealed refrigerant path; when separated, independent spring-loaded poppet valves in each half snap shut, containing system charge on both sides and admitting less than 0.15 cc of air per connection cycle.
The design is purpose-built for split and modular HVAC/R configurations where evaporator or other circuit components need to be swapped without recovering system charge. That makes this coupling pair a natural fit for the Kippkitts 1 kW air-air heat pump platform, where flexible hoses terminated with these quick-disconnects allow different evaporator modules to be connected and disconnected from the outdoor unit without releasing refrigerant or requiring re-evacuation. The all-brass body and refrigeration-grade copper sweat connections are chemically compatible with R32, R290, R454B, R600a, R410A, R22, R134a, R404A, R407C, and R507 — covering the full range of current and forward-looking low-GWP refrigerants relevant to residential and light-commercial heat pump design.
The metal-to-metal final seal formed when the union nut is fully tightened gives this coupling a connected leak rate under 0.1 oz of R22-equivalent per year — negligible for precision heat pump circuits where charge integrity is critical to COP. The thread-together design allows connection and disconnection under system pressure, meaning the circuit does not need to be depressurized before swapping an evaporator module in the field.
Key Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Parker Hannifin |
| Series | 5500 Self-Sealing Brass |
| Male half part number | 5502-04B-06 (with plastic cap) |
| Female half part number | 5505-04B-06 (with plastic plug) |
| Sold as | Matched male + female pair |
| Coupling body size | -06 (3/8" / 9.5 mm) |
| Copper connection size | -04 (1/4" ODF / 6.4 mm) |
| Connection type | Copper sweat (braze) |
| Coupling body material | Brass bar, ASTM-B16, Alloy C3600 |
| Connection material | Refrigeration-grade copper, ASTM-B75, Alloy C12200 |
| Internal assembly material | ASTM-B16 Alloy C360 & zinc trivalent chromate plated steel |
| Poppet seal (male) | Neoprene™ bonded poppet |
| Sleeve seal (female) | Neoprene™ bonded sleeve |
| Operating pressure (connected) | Vacuum to 750 psi (52 bar) |
| Operating pressure (male, disconnected) | Vacuum to 750 psi (52 bar) |
| Operating pressure (female, disconnected) | Vacuum to 600 psi (41 bar) |
| Minimum burst pressure (connected) | 2,700 psi (186 bar) |
| Minimum burst pressure (male, disconnected) | 2,700 psi (186 bar) |
| Minimum burst pressure (female, disconnected) | 1,800 psi (124 bar) |
| Operating temperature range | –40°F to +250°F (–40°C to +121°C) |
| Max air inclusion per connection | 0.15 cc |
| Max fluid loss per disconnection | 0.10 cc |
| Connected external leak rate | < 0.1 oz R22-equivalent per year |
| Disconnected leak rate (without cap/plug) | < 0.50 oz R22-equivalent per year |
| Disconnected leak rate (with cap/plug) | N/A — -06 body size does not include metal cap/plug option |
| Overall length, disconnected (female half) | 3.14 in (79.8 mm) |
| Overall length, disconnected (male half) | 2.58 in (65.5 mm) |
| Coupled overall length | 4.77 in (121.2 mm) |
| Union nut thread (female hex nut) | M20-1.5 |
| Coupling body hex (female) | 0.75 in (19.1 mm) across flats |
| Union nut hex (female) | 0.94 in (23.9 mm) across flats |
| Recommended connection torque (male to female) | 18–20 ft·lbs (24.4–27.1 N·m) |
| Refrigerant compatibility | R22, R32, R134a, R290, R404A, R407C, R410A, R454B, R507, R600a (and polyolester, PAG, mineral, and alkylbenzene oils) |
| Vibration resistance | UL 109 |
| RoHS compliant | Yes |
| Agency approvals |
UL Listed, File No. SA7511 |
Connection / Integration
Coupling Operation
The 5500 Series uses a thread-together union nut design with three sequential sealing stages:
- Disconnected — Spring-loaded poppets in both halves are closed. The male poppet seats against surface "A" of the male body; the female sleeve seats against the stem valve head at surface "B". An O-ring on the female sleeve provides secondary sealing in this state.
- Partially connected — As the union nut engages, the male body's sealing surface "C" contacts the female sleeve before either poppet opens. Both valves remain sealed during thread engagement, so refrigerant cannot escape even while the coupling is being assembled under pressure.
- Fully connected — Continued tightening draws the poppets open and simultaneously drives a metal sealing ring (located at the front face of the male coupling) into the brass seat of the female half, forming the primary metal-to-metal leak seal. Refrigerant flow path is now open.
Disconnecting under pressure is permitted. Reverse the above sequence; both poppets re-seat before any refrigerant path opens to atmosphere.
Torque values for the -06 body size:
| Joint | ft·lbs | N·m |
|---|---|---|
| Male half to female half (union nut) | 18–20 | 24.4–27.1 |
Use torque values above, or the marker/1/4-turn-past-contact method described in the assembly instructions. Do not rotate the female coupling body during tightening — only the union nut should turn.
Integration Notes
- Application context. In the Kippkitts 1 kW heat pump platform, these couplings are intended to terminate the flexible refrigerant hoses that connect the outdoor unit to swappable evaporator modules. The male half (5502) brazed to the system side, the female half (5505) on the evaporator module, is the recommended convention — this leaves the lower disconnected burst pressure on the female side (the removable component) and the higher-rated male half on the permanently plumbed system side.
- Tubing size transition. The Danfoss GBC16S ball valve (009L8053) paired with these couplings in the Kippkitts BOM has a 5/8" ODF connection. A short copper reducing stub (5/8" ODF → 1/4" ODF, or an intermediate step through 3/8" ODF) must be brazed between the valve and the coupling. This stub can be fabricated from refrigeration-grade ACR copper tubing. Parker also offers a range of braze adapters under the 202208-xx-4B part number family if a machined adapter is preferred.
- Brazing discipline. Use paste flux sparingly on the tube only — not on the coupling body. Protect the coupling with a flowing water bath or chill blocks during brazing to prevent internal seal damage. Quench the assembly below 400°F before releasing from the water bath. See Parker Catalog OEM-1 assembly instructions for full brazing procedure.
- Lubrication. Before each connection, wipe the rubber poppet and union nut threads with refrigeration-grade oil compatible with the system charge. For R290 and R600a (hydrocarbon) systems, use a polyolester oil. For R32/R454B systems, polyolester is also recommended. Do not use mineral oil with HFO or HFC refrigerants.
- Refrigerant oil compatibility. Parker confirms compatibility with R22 + mineral/alkylbenzene/POE/PAG oils, and R134a/R404A/R407C/R410A/R507 + polyolester oil. For R32, R290, R454B, and R600a, verify oil compatibility with your system oil supplier; Parker recommends contacting them directly for refrigerant oils not listed in the original datasheet.
- -06 body size cap/plug limitation. The -06 coupling body size does not have a metal protective cap/plug option — only plastic (included with B-suffix parts). Store and ship with plastic caps/plugs installed and reinstall them when the evaporator module is disconnected from the system. Inspect the Neoprene poppet and sleeve seals for damage before reconnecting after extended storage.
- Connection under pressure. The coupling can be connected and disconnected under operating system pressure (up to 750 psi on the male side). Ensure coupling faces are parallel and free of lateral load before starting the union nut by hand. If the nut does not start freely by hand, do not force it — realign the hose to remove side-load before threading.
- MTBF/L10 life. Cycle life and MTBF data are not published in Parker Catalog OEM-1 for this series. Contact Parker Hannifin A/C & Refrigeration Aftermarket (Washington, MO) for MTTF data if long-life or high-cycle-count qualification is required for your application.
- Parallel use. Each coupling half is an independent sealed unit. Multiple pairs can be used in parallel circuits (e.g., liquid line and suction line) without interaction. Route the suction-line coupling where it is accessible for the higher torque values that may result from larger body sizes in future kit revisions.
Included Accessories
- 1× Parker 5502-04B-06 male coupling half (with plastic protective cap)
- 1× Parker 5505-04B-06 female coupling half (with plastic protective plug)
Braze adapters, reducing stubs, and flexible hose assemblies are sold separately.