TES-LOK Female Bulkhead Connector Tube Fittings — double-ferrule compression tube inside the panel, female NPT / BSP internal thread outside the panel. Sealed tube-to-female-thread panel feedthrough in one fitting. SS 316 · Brass · Monel · Inconel · Equal & Reducing · Up to 6,000 PSI · ISO 9001:2015 certified.
Female Bulkhead Connector (Equal)
Bulkhead Reducer (Reducing variant)
A female bulkhead connector tube fitting is a panel-mount fitting that creates a sealed tube-to-female-thread feedthrough through any enclosure wall, bulkhead, or panel. The hex body passes through a drilled panel hole; a panel nut (locknut) on the inside face clamps the fitting shoulder against the outside panel face, creating a gas-tight panel seal with no additional sealing materials.
Inside the panel: a double-ferrule compression tube connection (TES-LOK bite-type) forms the leak-tight joint with the internal tube run. Outside the panel: a female internal NPT or BSP thread socket receives a male-threaded stud, nipple, or instrument port from external equipment. This is the mirror of the male bulkhead connector — both pass through the panel in the same way; the female bulkhead is used when the external equipment presents a male-threaded connection.
| Port | Location | Connection Type | Function |
|---|---|---|---|
| Port 1 | Inside panel | Double-ferrule compression tube (TES-LOK) | Connects to internal tube run (1/16"–1" OD) |
| Port 2 | Outside panel | Female internal thread — NPT, BSPT, BSPP, UNF | Receives male-threaded stud, nipple, or equipment outlet port |
| Panel nut | Inside panel face | Hex locknut on body threads | Clamps body shoulder against outside panel face — secures fitting in panel |
| Fitting | Inside Panel (tube side) | Outside Panel (equipment side) | Use When External Equipment Has… |
|---|---|---|---|
| Female Bulkhead Connector | Compression tube | Female internal thread | Male-threaded stud, nipple, or projecting male port |
| Male Bulkhead Connector | Compression tube | Male external thread | Female-threaded inlet socket or port |
| Bulkhead Union | Compression tube | Compression tube | No threads — tube-to-tube feedthrough; tube run continues through the panel |
On the outside-panel female-thread end, the sealant is applied to the male thread of the mating stud or nipple that enters the female socket — not to the female socket itself:
| Mating Male Thread Type | Sealant Applied To | Sealant |
|---|---|---|
| NPT (tapered American) | Male thread of mating stud/nipple | PTFE tape (2–3 wraps) or anaerobic thread sealant |
| BSPT (tapered British) | Male thread of mating stud/nipple | PTFE tape (2–3 wraps) or anaerobic thread sealant |
| BSPP (parallel British) | Flat face of mating male port | Bonded seal (Dowty washer) — no PTFE on BSPP |
| UNF / SAE straight thread | Shoulder of mating male thread | O-ring on male shoulder per thread specification |
| TES-LOK Female Bulkhead Connector Tube Fitting — Specifications | |
|---|---|
| Brand | TES-LOK (by Tesco Steel & Engineering) |
| Inside panel end | Double-ferrule compression tube (TES-LOK bite-type) |
| Outside panel end | Female internal thread — NPT · BSPT · BSPP · UNF · SAE |
| Panel mount | Hex body through panel hole; panel locknut on inside face included |
| Tube OD range | 1/16" – 1" (imperial) · 3 mm – 25 mm (metric) |
| Thread range | 1/16" NPT – 3/4" NPT and equivalent BSP |
| Configurations | Equal · Reducing |
| Body materials | SS 316 / 316L (standard) · SS 304 · Brass · Monel 400 · Inconel 600 · Hastelloy C-276 |
| Max. working pressure | 6,000 PSI (SS 316) · 3,000 PSI (Brass) |
| Temperature range | −196°C to +400°C (SS) · −29°C to +260°C (Brass) |
| Standards | ASTM D1710 · ASTM D3294 |
| Certifications | ISO 9001:2015 · EN 10204 3.1 MTC available |
| Compatible systems | TES-LOK · Swagelok · Parker A-LOK · Ham-Let |
A female bulkhead connector consolidates the panel penetration, tube connection, and female-thread socket in one machined body. No separate panel grommet, compression union, or female adapter required. The shoulder-to-panel contact is the panel seal — no additional sealing components at the panel hole.
The outside-panel female socket receives male NPT, BSP, or UNF instrument stubs directly — no intermediate nipple required. Instruments, gauges, and analysers with male-threaded process connections attach directly to the female socket of the bulkhead connector on the outside panel face, eliminating additional union connections in the tube run.
The inside-panel compression end uses the TES-LOK double-ferrule mechanism — front ferrule bites the tube OD, rear ferrule spring-loads against the body for vibration damping. Essential for panels on pump skids, offshore platforms, and any installation subject to structural vibration.
Reducing female bulkhead connectors connect different tube OD inside the panel to different female thread size outside — eliminating a separate reducing adapter at the panel wall. Useful when instrumentation tubing OD and the male thread size of the external equipment stud do not match.
Available in SS 316, Monel 400, Inconel 600, and Hastelloy C-276 with matching CRA ferrules. EN 10204 3.1 material test certificates and PMI testing available — meeting oil and gas, chemical, and EPC procurement documentation requirements.
Manufactured under ISO 9001:2015 quality management system. Each assembly is hydrostatic pressure-tested before dispatch. Full traceability from raw material heat to finished fitting is maintained under the TES-LOK quality system.
▶ What is a female bulkhead connector tube fitting?
A female bulkhead connector tube fitting creates a sealed tube-to-female-thread feedthrough through a panel wall. Hex body through panel hole; locknut on inside face. Inside: compression tube. Outside: female internal thread that receives a male-threaded stud or nipple from external equipment.
▶ What is the difference between a female bulkhead and a male bulkhead connector?
Both pass through the panel the same way. A female bulkhead connector has a female internal socket on the outside-panel end — it receives a male-threaded stud from external equipment. A male bulkhead connector has a male external stud — it screws into a female-threaded port on external equipment. Choose based on the thread type of the external equipment connection.
▶ How is a female bulkhead connector installed?
Pre-load the panel nut, insert the female-thread end from outside through the panel hole, tighten the panel nut from inside (snug plus one full turn). Apply PTFE tape to the male thread of the external equipment stud (NPT/BSPT) or bonded seal for BSPP. Thread the male stud into the female socket using a back-up wrench on the body flats. Make the compression tube connection inside last.
▶ What tube OD sizes are available?
1/16" to 1" imperial and 3 mm to 25 mm metric. Female thread from 1/16" NPT to 3/4" NPT and equivalent BSP. Equal and reducing configurations both available.
▶ What is the maximum pressure rating?
Up to 6,000 PSI in SS 316 at ambient temperature. Brass to 3,000 PSI. The panel nut and bulkhead body do not reduce the pressure rating.
▶ What is the thread sealant rule for female bulkhead connectors?
Sealant goes on the male thread of the mating stud entering the female socket. PTFE tape for NPT/BSPT tapered threads. Bonded seal (Dowty washer) for BSPP parallel thread — no PTFE on BSPP. No sealant on the compression tube end — the ferrule bite seals on the tube OD.
▶ What materials are available?
SS 316 (standard), SS 316L, SS 304, Brass, Monel 400, Inconel 600, and Hastelloy C-276. Ferrules in matching material. EN 10204 3.1 MTCs and PMI available on request.
▶ Can female bulkhead connectors be used in hazardous area panels?
Yes. TES-LOK female bulkhead connectors are used in Ex-rated instrument panels on offshore platforms and petrochemical sites where tube lines must enter or exit classified-area enclosures. The metal-to-metal shoulder seal at the panel face provides a flame-path-free tube feedthrough when used with appropriate panel materials and thickness. Consult your hazardous area design authority for specific Ex-e enclosure tube entry requirements.
Equal & Reducing · SS 316 · Brass · CRA Alloys · NPT · BSP · 1/16"–1" Tube OD · Up to 6,000 PSI
ISO 9001:2015 · EN 10204 3.1 MTC · Fast delivery worldwide