Port Connector Tube Fittings: Stainless Steel & High-Nickel Alloy
A port connector is an instrumentation compression tube fitting used to join two female tube-fitting ends, or to seat a tube fitting directly into a female instrument port. It's a single component: a fixed male tube stub on one end, a tube-fitting nut and ferrule on the other. No added length of tubing is needed to make the connection.
Crestflo supplies port connector tube fittings for the US market in 316/316L stainless, along with duplex, super-austenitic, and high-nickel alloys. Fittings come single or double ferrule, spanning imperial and metric sizes up to 2 in (50 mm) OD. Each part carries a heat-number mark and meets ASTM F1387. It also drops in dimensionally for the major instrumentation brands. We Engineer Confidence.
Scope note: on this page, "port connector" refers to a fluid-system instrumentation tube fitting. Think stainless-steel or alloy compression component. It's not an electrical, USB, network, or panel-data port connector.
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What Is a Port Connector Tube Fitting?
A port connector tube fitting is a stub-style compression fitting that joins two female tube-fitting bodies to each other, or ties a tube run into a female instrument, gauge, or valve port, all in one piece. One end carries the tube-fitting nut and ferrule set that grips a tube. The opposite end is a machined male tube stub, sized to enter a mating female tube-fitting body and get sealed by that body's own nut and ferrule. The stub stands in for a short cut of tube, so the port connector cuts out an assembly step and removes a potential leak path from close-coupled hookups. On drawings it's specified as an instrumentation port connector, or instrument port connector, and it belongs to the same compression tube-fitting family as the union and the connector.
Crestflo makes several tube-fitting variants, and this one is defined by which ends it presents. A union joins two tube ends, both held by compression ferrules. A connector or adapter takes a tube-fitting end and transitions it to a threaded or different end type. A port connector works differently: it presents one tube-fitting end and one male tube-stub end, letting it plug two female ports together. For the full range of configurations, including PED-rated options, see the instrumentation tube fittings hub.
Also Known As: Stub Port Connector, PC Fitting & Tube-to-Port Connector
Buyers and specifiers call this component by a lot of names. You'll see it specified as a port connector fitting, a tube fitting port connector, a stub port connector, or a tube stub connector, that last pair named for its male stub end. Some call it a port connector adapter. Others just say PC fitting. Catalogs don't make things any simpler: Swagelok lists it under the "-PC" designation, Parker's A-LOK line uses the "PC" series (a 6PC6-T call-out, for instance), and S-Lok runs its own "SCP-" series. Each of these names belongs to its respective trademark owner, so don't expect them to line up neatly across brands. No matter what label shows up on your drawing or bill of materials, though, you're looking at the same part: the female-to-female stub joiner described here.
Port Connector Sizes (1/16 in–2 in, 3 mm–50 mm) & Ferrule Options
Crestflo port connectors cover the full standard instrumentation tube-OD range, available in both fractional-imperial and metric series. Single-ferrule or double-ferrule end preparation is available, whichever suits the specification you're matching. Below, the size grid lists the standard tube ODs on offer, so you can pick the port connector dimensions that match your line. Port connector fitting dimensions follow the applicable tube-OD standards, and they can be customized to requirement.
| Series | Standard tube ODs served | Ferrule preparation |
|---|---|---|
| Imperial (fractional) | 1/16, 1/8, 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, 7/8, 1, 1‑1/4, 1‑1/2, 2 in | Single or double ferrule |
| Metric | 3, 6, 8, 10, 12, 14, 16, 18, 20, 22, 25, 28, 32, 38, 50 mm | Single or double ferrule |
Ferrules come hardened or non-hardened, whichever the application calls for. Where a gripless, ferrule-less end preparation is needed, a ferrule-less port connector is available too. Check the ferrule-less tube fittings range for details.
For a particular configuration, the tube fitting size chart is a good starting point. The single-ferrule range and the metric tube fittings series cover other needs. Common sizes, like 1/4-inch and 1/2-inch tube fittings, are listed separately.
Port Connector Materials: 316/316L Stainless, Duplex, Inconel, Monel & Hastelloy
Crestflo machines its port connectors from the same corrosion-resistant and high-nickel alloys used across the rest of its tube-fitting line. That keeps the fitting matched to the tubing and to the environment it'll serve. Stainless grades cover general instrumentation needs. Duplex and 6-moly grades stand up to chloride exposure and pitting. Nickel alloys are the choice for sour, acidic, and high-temperature service. Brass, aluminum, and copper port connectors aren't part of the lineup.
| Family | Grades | UNS | Typical selection driver | Material page |
|---|---|---|---|---|
| Austenitic stainless | 304/304L, 316/316L, 904L | S30400/S30403, S31600/S31603, N08904 | General service; 316L default | 316/316L |
| Duplex / super-duplex | 2205, 2507 | S32205, S32750 | Chloride & stress-corrosion resistance | Duplex 2205 · 2507 |
| Super-austenitic | 254 SMO, AL-6XN, Alloy 20 | S31254, N08367, N08020 | Seawater & high-chloride media | 254 SMO |
| Nickel alloys | Inconel 625/825, Monel 400, Hastelloy C-276 | N06625, N08825, N04400, N10276 | Sour, acidic & high-temperature service | Inconel 625 · Monel 400 · Hastelloy C-276 |
| Titanium | Grade 2 | R50400 | Light-weight, high corrosion resistance | Materials index |
Compositions meet the relevant ASTM and UNS specifications, and each one can be adjusted to match specific requirements. Coverage spans the full alloy range: Inconel 600/601/718, Incoloy 800/800H, Monel K500, Hastelloy C-22/B-2/B-3/X, Nickel 200/201, and titanium Gr2. You'll find the complete list on the materials index.
Port Connector Pressure & Temperature Ratings
It's the mating tube that sets the working pressure of a port connector, not the stub. OD, wall thickness, alloy: these govern, following the standard instrumentation tube working-pressure tables and the allowable-stress basis of ASME B31.3. Temperature capability, meanwhile, comes down to the alloy. A metallic tube fitting carries no elastomeric seal, so the ceiling is simply the material's allowable-stress range under the applicable ASTM/ASME specification. Figures follow the applicable standard and can be tailored to what's needed. Give us your tube size, wall, alloy, and service conditions on the RFQ, and our engineers will confirm the governing rating.
The port connector is a compression tube fitting, qualified to ASTM F1387, the standard covering gauge, torque, vibration, pressure, and impulse behavior for instrument fittings. High-pressure cone-and-thread service sits in a separate product line. It isn't covered under this configuration.
Interchange: A Drop-In Alternative to Swagelok, Parker A-LOK & Hy-Lok Port Connectors
Crestflo port connectors are built as a dimensional match, a drop-in replacement, for the port connectors made by Swagelok, Parker A-LOK, Hy-Lok, Hoke, GYROLOK®, and Fitok. That claim rests on ASTM F1387 performance qualification, not on parts-interchangeability alone. It covers the Swagelok port connector assembly and the equivalent instrument port connector call-outs that distributors stock. Swagelok is a trademark of Swagelok Company. Parker and A-LOK belong to Parker Hannifin. GYROLOK is a trademark of Circor/Hoke, and Hy-Lok, Hoke, and Fitok are trademarks of their respective owners. Crestflo isn't affiliated with, authorized by, or endorsed by any of these companies. These marks appear here only to describe dimensional equivalence.
We don't keep a fixed brand-to-Crestflo part-number table on hand. Send us the brand series, size, and material you're replacing, and our engineering team will send back the matching Crestflo specification for your exact line items. Start at the Swagelok cross-reference, the Parker A-LOK cross-reference, or the Hy-Lok cross-reference. Or just request your cross-reference directly.
Port Connector Applications: Gauge Hookups, Sampling Systems & Instrument Air
Port connectors do the job wherever two female tube-fitting ports need to meet without running a tube between them: gauge and instrument hookups, close-coupled manifold and valve stacks, analytical and process sampling systems, instrument air distribution, panel-mount instrument enclosures, and hydraulic control lines. Because they're built entirely of metal with traceable alloy, Crestflo connectors hold up in critical service, where a leak-tight joint that can still be serviced later isn't optional.
Standards, Certifications & Traceability
| Item | Scope | Basis |
|---|---|---|
| ASTM F1387 | Compression tube-fitting performance qualification | Interchange substantiation |
| NACE MR0175 / ISO 15156 | Sour-service material requirements | In the appropriate alloys, NACE MR0175 |
| ASTM A269 / A479 / A276 | Tubing and bar-stock feedstock | Traceable raw material |
| EN 10204 MTC | Material test certificate | 3.1 standard, 3.2 on request |
| Heat/lot marking | Traceability on every part | Positive material identification available |
| Management systems | ISO 9001 / 14001 / 45001 & PED certified | Certificates held in Quality |
Compositional and performance values follow the applicable standard. Approvals here are stated as conformance, not as numbered certificates on this page. Certificates themselves live in the quality and traceability sections. Datasheets and CAD models are available to Crestflo customers on request.
Request Port Connector Fittings: RFQ, Samples & Distributor Program
Ready stock covers standard items. Specials are made to order, with delivery running 6-8 weeks. Small minimum order quantities are available, and OEMs and distributors can take advantage of private-label programs.
- Request a quote, send your size, alloy, and ferrule requirement
- Swagelok, Parker, or Hy-Lok, whatever brand you're running, Crestflo can match it. Request a cross-reference and we'll line up the equivalent parts for you.
- Download the catalog, full instrumentation fitting range
- Talk to our engineering team, design-in, made-to-print, and kitting support
US sales: sales@crestflousa.com · +1 346 594 9005 · Houston, TX.
Why Crestflo for Port Connector Tube Fittings
Crestflo sits as the instrumentation arm of an export house that's been in business for four decades, one recognized by the Government of India, with a long record of delivering into the Middle East. That background stands behind a fitting program built for the US market and designed for drop-in replacement: ASTM F1387-qualified interchange, sizes in both imperial and metric, single and double ferrule options, ferrules hardened or non-hardened, and finishes running from material finish and passivation through to electropolish and silver anti-galling plating. Each part carries a heat-number mark and EN 10204 MTC 3.1 documentation, with 3.2 available on request. Standard product comes from India, though US or European melt can be arranged on request, and full material traceability is included. Delivery runs 6-8 weeks. The majors typically need 20-plus.
Frequently Asked Questions
What is a port connector tube fitting?
A port connector is a stub-style compression fitting that joins two female tube-fitting ends in a single piece, or connects a tube fitting to a female instrument port. One end carries a tube-fitting nut and ferrule; the other has a fixed male tube stub. No extra length of tubing is needed to complete the joint.
What is a Swagelok port connector?
Swagelok is a trademark of Swagelok Company. Its port connector uses the same stub configuration described here. Crestflo port connectors are a dimensional interchange, a drop-in equivalent, qualified under ASTM F1387. The mark, though, is used only to describe dimensional equivalence; Crestflo isn't affiliated with or endorsed by Swagelok.
How is a port connector different from a union or an adapter?
A union brings two tube ends together, each one gripped by its own compression ferrule. An adapter, or a connector, shifts a tube-fitting end over to a threaded end or some other end type entirely. A port connector works differently: it joins two female tube-fitting ports through a male tube stub. For the PED specifications on each, see Crestflo's union, adapter, and connector pages.
What is a tube adapter?
A tube adapter converts a tube-fitting end into a different end type, whether that's a thread or a different OD, rather than joining two matching ports. That's a different setup from a port connector. Check the adapter tube fitting page for more.
What sizes and ferrule options are available?
Crestflo port connectors cover the standard instrumentation tube-OD range from 1/16 in to 2 in (roughly 3 mm to 50 mm), available in both imperial and metric series. Single-ferrule or double-ferrule preparation is offered, and ferrules can be hardened or non-hardened depending on the requirement. Sizes follow the applicable standard and can be customized.
What materials are port connectors made from?
Material options run wide: 316 and 316L, 304 and 304L stainless, 904L, duplex 2205, super-duplex 2507, 254 SMO, AL-6XN, and Alloy 20. Nickel alloys are also available, including Inconel, Monel, and Hastelloy, along with titanium Grade 2. Brass, aluminum, and copper aren't part of Crestflo's lineup.
Are port connectors available NACE-compliant for sour service?
Yes. We offer port connectors compliant with NACE MR0175 / ISO 15156 in the appropriate alloys for sour-service applications. Check the NACE MR0175 page for scope.
Do Crestflo port connectors replace Swagelok, Parker, or Hy-Lok fittings?
They're built as a dimensional drop-in interchange, qualified against ASTM F1387 performance standards. There's no fixed part-number table we publish. Send us your brand, series, size, and material, and we'll return the matching Crestflo specification. Start a cross-reference request.
What certification comes with each part?
Each part comes stamped with a heat/lot number and ships with an EN 10204 MTC 3.1 material test certificate; 3.2 is available on request. Positive material identification can be arranged as well. Crestflo runs management systems certified to ISO 9001, 14001, 45001, and PED.
What are the lead time and minimum order quantity?
Standard items ship from stock. Specials get made to order, and delivery runs 6-8 weeks. Minimum order quantities stay small, and OEMs and distributors can tap into private-label programs.
Where are Crestflo port connectors made?
Standard product comes from India, though US or European melt is available on request, with full material traceability throughout. Crestflo serves the US market, built for drop-in replacement and delivered in 6-8 weeks.
Related Fittings & Resources
- Instrumentation tube fittings, full configuration range
- Union · Adapter · Connector, related configurations
- Nut and ferrule · Ferrules, the parts that actually seal
- ASTM F1387 · EN 10204 MTC, the standards Crestflo builds to
- Swagelok cross-reference · Parker A-LOK cross-reference