Instrumentation Fittings, Valves & Tubing for Hydraulic Systems
Instrumentation fittings, valves and tubing for hydraulic systems are the corrosion-resistant, high-pressure components that connect the control, sensing and actuation lines of a hydraulic circuit. The connective tissue of the circuit, in effect. Tube fittings, bite-type and flare connections, needle and check valves, manifolds and instrument tubing all fall under that heading, and together they link power units, accumulators, actuators, gauges and subsea controls.
Crestflo supplies this whole building set to US hydraulic OEMs, EPC and panel fabricators, and MRO buyers: compression tube fittings, DIN 2353 bite-type fittings, 37° JIC flare fittings, cone-and-thread high-pressure fittings, instrumentation valves, hydraulic tubing and pressure snubbers. All of it's available in 316/316L through duplex and high-nickel alloys, and it ships with heat-number traceability on a 6-8 week lead time.
On this page, "hydraulics" refers to the instrumentation, control and high-pressure sensing side of hydraulic systems: the fittings, valves and tubing that connect power units, accumulators, actuators, gauges and subsea controls. Rubber hydraulic hose, crimp or hose-end assemblies, and hose adapters aren't covered here. And wherever you see "ferrule" on this page, it means a fluid-system compression ferrule, not an electrical one.
Also Known As: Hydraulic Tube Fittings, Bite-Type, JIC Flare & High-Pressure Fittings
Names for these parts multiply across engineering drawings and RFQs, but Crestflo stocks them all in stainless and alloy. A hydraulic schematic might list them as hydraulic instrumentation fittings, hydraulic tube fittings, stainless steel hydraulic fittings, high-pressure hydraulic fittings, hydraulic compression fittings, or hydraulic ferrule fittings. Bite-type connections go by DIN 2353 or ISO 8434-1. Call a 37° flare connection a JIC fitting, and it's built to SAE J514 and ISO 8434-2. High-pressure lines get labeled cone-and-thread fittings instead. Valve callouts run just as wide: hydraulic needle, ball, check (NRV), relief, metering, bleed, gauge-root and manifold valves, plus monoflange and double-block-and-bleed valves. HPU fittings, accumulator fittings and hydraulic control-line fittings round out the list.
Where Hydraulic Instrumentation Fittings & Valves Are Used
A hydraulic system runs several distinct high-pressure lines, and each one carries its own demands around pressure, pulsation and corrosion. The table below maps common hydraulic sub-systems to the in-scope Crestflo component, along with the connection type that typically serves them.
| Hydraulic sub-system | Typical Crestflo component | Common connection |
|---|---|---|
| Power units (HPUs) & pump manifolds | Tube fittings, needle valves | DIN 2353, NPT, JIC |
| Accumulator sensing & charging lines | Cone-and-thread fittings, check valves | High-pressure, tube OD |
| Actuator & servo control lines | Bite-type fittings, metering valves | DIN 2353, JIC 37° |
| Gauge & transmitter hook-ups | Gauge-root valves, snubbers | NPT, tube-fitting |
| Subsea & offshore control umbilicals | Duplex tube fittings, monoflange valves | Tube OD, flanged |
| Test rigs & hydraulic test benches | High-pressure fittings, relief valves | Cone-and-thread, JIC |
These lines carry over into other areas Crestflo serves too: oil and gas, offshore, subsea, and marine and shipbuilding hydraulics. The program supplies the US market. Standard items sit in ready stock, specials are made to order, and alloy or high-pressure configurations, the kind most hydraulic builds call for, take 6–8 weeks.
Hydraulic Fitting Families: Compression, DIN 2353 Bite-Type, JIC Flare & Cone-and-Thread
Four fitting families handle the connection side of a hydraulic system. Each row links out to the product page that carries the full ordering detail. Datasheets and CAD files? Available to customers on request.
| Fitting family | Standard | Max working pressure | Size range | Product page |
|---|---|---|---|---|
| Compression (single & double ferrule) | ASTM F1387 tested | Rating per size/series | Up to 2″ (50 mm) OD | Tube fittings |
| DIN 2353 bite-type | DIN 2353 / ISO 8434-1 | Rating per series (L/S) | Metric tube OD | DIN 2353 fittings |
| 37° JIC flare | SAE J514 / ISO 8434-2 | Up to 15,000 PSI | Up to 2″ OD | 37° JIC flare fittings |
| Cone-and-thread high-pressure | High-pressure design | Up to 30,000 PSI | Per bore/series | Cone-and-thread fittings |
Crestflo's compression fittings come with hardened or non-hardened ferrules, in single-ferrule and double-ferrule (twin-ferrule) configurations, and each is tested per ASTM F1387. Ratings follow the applicable standard and size or series. Values can be adjusted to fit specific requirements.
Hydraulic End Connections & Threads: NPT, BSPP/BSPT, JIC 37°, SAE ORB & DIN 2353
Hydraulic fittings connect to pumps, valves and manifolds through a defined set of threads and end connections. The table below lists each connection, the standard that governs it and its Crestflo sub-page.
| Thread / end connection | Standard | Sizing | Sub-page |
|---|---|---|---|
| NPT tapered pipe thread | ASME B1.20.1 | Imperial | NPT tube fittings |
| BSPP / BSPT | ISO 228 / ISO 7 | Imperial (BSP) | BSPP, BSPT |
| JIC 37° flare | SAE J514 / ISO 8434-2 | Imperial | JIC-37 tube fittings |
| SAE O-ring boss (ORB) | SAE J1926 | Imperial | SAE ORB fittings |
| DIN 2353 bite-type | ISO 8434-1 | Metric tube OD | DIN 2353 fittings |
| Metric & imperial tube OD | Per tube size chart | Both | Metric, imperial |
Every fitting family comes in both metric and imperial sizes. Need to compare threads and connections? Check the JIC vs DIN 2353 and JIC vs ORB guides, or pull up the tube fitting size chart.
High-Pressure Hydraulic Fittings: 3,000 to 30,000 PSI
Proof, burst and impulse testing back up the hydraulic service rating for high-pressure work. That impulse and vibration regime is built for pulsating hydraulic circuits. Crestflo runs a full pressure ladder, from standard duty up through cone-and-thread designs, and each class links straight to its own product page.
| Pressure class | Fitting type | Product page |
|---|---|---|
| 3,000 PSI | High-pressure fittings & valves | 3,000 PSI |
| 6,000 PSI | High-pressure fittings & valves | 6,000 PSI |
| 10,000 PSI | High-pressure fittings & valves | 10,000 PSI |
| 15,000 PSI | Precision high-pressure fittings | 15,000 PSI |
| 20,000 PSI | High-pressure fittings & valves | 20,000 PSI |
| 30,000 PSI | Cone-and-thread fittings | Cone-and-thread |
Precision fittings top out at 15,000 PSI. Cone-and-thread designs go further, up to 30,000 PSI. Crestflo's full high-pressure program spans several distinct pressure classes, each one built to a different standard and size. Values can be tailored to what the job requires.
Valves for Hydraulic Control: Needle, Ball, Check, Relief, Metering & Manifold
Crestflo supplies the instrumentation valve set used to isolate, meter, protect and connect hydraulic control lines. Every valve meets ASME B16.34 and the applicable API valve standards. The double-block-and-bleed valve is designed specifically per ASME B16.34.
| Valve | Function in a hydraulic circuit | Product page |
|---|---|---|
| Needle valve | Fine flow control & isolation | Needle valve |
| Ball valve | Full-port on/off isolation | Ball valve |
| Check valve / NRV | Non-return / anti-backflow | Check valve, NRV |
| Relief valve | Over-pressure protection | Relief valve |
| Metering valve | Precise flow metering | Metering valve |
| Bleed valve | Venting & depressurization | Bleed valve |
| Gauge-root valve | Gauge / transmitter isolation | Gauge-root valve |
| 2/3/5-valve manifold | Instrument hook-up & calibration | 3-valve manifold |
| Monoflange valve | Compact primary isolation | Monoflange valve |
| Double block & bleed | Positive isolation per B16.34 | DBB valve |
Crestflo manifolds come in 2-valve, 3-valve and 5-valve configurations, and every unit gets 100% seat and shell leak testing. Pressure ratings run up to 10,000 psi for the manifolds and up to 3,000 psi for double-block-and-bleed valves. Those figures follow the applicable standard, but they're adjustable to what a project actually needs.
Hydraulic & Instrumentation Tubing in Stainless and Alloy
Crestflo supplies stainless steel and alloy hydraulic tubing in both seamless and welded forms, annealed for bending, available in imperial and metric OD. The tubing meets base specifications like ASTM A269, with dimensions following standard tube tables. It can also be customized to specific requirements.
| Tubing form | Typical use | Product page |
|---|---|---|
| Hydraulic tubing | High-pressure control & sensing lines | Hydraulic tubing |
| Seamless tubing | Higher-pressure seamless runs | Seamless tubing |
| Coiled tubing | Continuous control-line runs | Coiled tubing |
| Alloy tubing | Corrosive / seawater control fluids | Alloy tubing |
See the tubing size chart for OD and wall selection.
Alloy Selection for Hydraulic Environments: 316L, Duplex, 6Mo & High-Nickel
Hydraulic fluid and the external environment decide which alloy fits. 316/316L covers general duty. Once chloride, seawater or sour-service circuits enter the picture, though, the spec moves up to duplex and high-nickel corrosion-resistant alloys. You'll find composition, PREN and corrosion detail on each material page; the table lays out the selection logic and links to each one.
| Environment / fluid | Corrosion driver | Recommended alloy | Material page |
|---|---|---|---|
| General mineral / synthetic hydraulic fluid | Baseline duty | 316/316L | 316/316L |
| Water-glycol & mild chloride | Pitting risk | 904L | 904L |
| Marine / chloride control fluids | Chloride pitting & SCC | Duplex 2205 | Duplex 2205 |
| Seawater control & subsea | Severe chloride | Super Duplex 2507 / 254 SMO | Super Duplex 2507, 254 SMO |
| Sour (H₂S) hydraulic service | Sulfide stress cracking | Inconel 625 / NACE grades | Inconel 625 |
| Aggressive / mixed acids | Broad corrosion | Hastelloy C-276 | Hastelloy C-276 |
| HF / reducing media | Fluoride attack | Monel 400 | Monel 400 |
| Weight-sensitive / high-CRA | Corrosion + weight | Titanium Gr2 | Titanium Gr2 |
Crestflo covers each grade in broad terms, but it only supplies material in instrumentation forms: fittings, valves and tubing. Bar, sheet, plate and mill product aren't part of the offering. Want a structured walk-through? Check the material selection by service and sour-service selection per NACE guides.
Standards, Testing & Traceability for Hydraulic Fittings & Valves
Crestflo holds the standard approvals that apply to each product type. Fittings meet ASTM F1387 for dimensional-interchange performance and NACE MR0175 for sour-service requirements. Valves qualify to ASME B16.34, plus the applicable API valve standards. You'll find the governing references and their standard pages in the table below.
| Standard | What it governs | Relevance | Standard page |
|---|---|---|---|
| ASTM F1387 | Compression tube-fitting performance | Fitting interchange qualification | ASTM F1387 |
| ASME B16.34 | Valve pressure-temperature design | Valve & DBB qualification | ASME B16.34 |
| NACE MR0175 / ISO 15156 | Sour-service metallic materials | H₂S hydraulic circuits | NACE MR0175, ISO 15156 |
| ASME B1.20.1 | NPT pipe threads | Threaded end connections | ASME B1.20.1 |
| ASTM A269 / A479 / A276 | Tubing & bar-stock bodies | Base material specs | A269, A479, A276 |
| EN 10204 | Material test certificate type | Traceability | EN 10204 MTC |
The testing regime covers hydraulic proof, hydraulic burst and hydraulic impulse, plus pneumatic, flexure fatigue, rotary flex, vibration, thermal cycling, pull-out and vacuum testing. Every part carries a heat/lot number backed by EN 10204 MTC 3.1 as standard, with 3.2 available on request. Positive material identification (PMI) confirms the alloy on both incoming material and finished parts. In-house NDT is backed by destructive testing at ISO/IEC 17025-accredited laboratories, and third-party inspection can be arranged on request. Hydraulic manifolds and assemblies get 100% seat and shell leak testing, no exceptions. Crestflo holds ISO 9001 / 14001 / 45001 & PED certification; see heat-number traceability & MTC and the full testing and inspection capability. Values follow the applicable standard and can be tailored to requirement.
Why Crestflo for Hydraulic Instrumentation Fittings & Valves
Crestflo is the instrumentation division of an export house that's been in business for four decades and carries Government of India recognition, with a solid delivery record across the Middle East. It now serves US hydraulic OEMs and MRO buyers directly, operating as a manufacturer built for the US market. Here's what actually matters to a hydraulic buyer:
- Delivery that fits a build schedule, Standard items ship from stock; specials are made to order. Either way, 6–8 week delivery beats the 20-plus weeks that's typical from the majors.
- Drop-in interchange, proven, These fittings match dimensionally and carry qualification to ASTM F1387. Rather than guess at part numbers, ask our engineering team for a Swagelok® cross-reference or Parker A-Lok cross-reference. Swagelok® and Parker® are trademarks of their respective owners; Crestflo has no affiliation with either.
- Both imperial and metric, Every fitting family comes in fractional and metric sizes, up to 2″ (50 mm) OD on fittings and 1/16″–1″ on valves.
- Alloy depth, 316/316L, duplex, super duplex, 254 SMO, Inconel, Monel and Hastelloy, all ready for chloride, seawater and sour hydraulic service.
- Small MOQ, private label and OEM, We run private-label and custom made-to-print programs built for equipment builders.
- Honest origin, Origin is Indian. US and European melt can be arranged on request, and full material traceability and country-of-origin support backs it up.
We Engineer Confidence. To reach the US sales team, email sales@crestflousa.com or call +1 346 594 9005 (Houston, TX). That's Crestflo, ready to help.
Frequently Asked Questions
Where can I buy stainless-steel and alloy fittings for hydraulic systems?
Crestflo is a US-serving manufacturer of instrumentation fittings, valves and tubing for hydraulic control, sensing and high-pressure lines, delivered drop-in with ready stock for standard items, made-to-order for specials and 6–8 week delivery. Request a hydraulics RFQ to start.
What types of fittings are used in hydraulic instrumentation?
We offer double- and single-ferrule compression tube fittings, DIN 2353 bite-type fittings, 37° JIC flare fittings, and cone-and-thread high-pressure fittings. Threaded ends come in NPT, BSPP/BSPT and SAE ORB as well. Every family's available in both metric and imperial sizes.
What does JIC mean in hydraulic fittings?
Crestflo makes 37° JIC flare fittings that handle up to 2″ OD and 15,000 PSI, and you can pair them with compression fittings on the same line. JIC itself is the 37° flare connection standardized as SAE J514 and ISO 8434-2.
How do I tell a JIC fitting from an SAE 45° flare?
Both are flare fittings, but the seat angles differ. JIC sits at 37°, while the common SAE automotive flare comes in at 45°. Confirm the angle before interchanging them. Crestflo offers both 37° JIC and 45° SAE flare fittings.
What pressure can Crestflo hydraulic fittings handle?
Precision fittings carry a rating up to 15,000 PSI, and cone-and-thread designs go as high as 30,000 PSI. Hydraulic proof, burst and impulse testing confirm those figures. Ratings follow the applicable standard and size, and they can be tailored to what's required.
Which alloys suit hydraulic systems in marine or sour service?
316/316L covers general duty work. For chloride and seawater control fluids, go with Duplex 2205, Super Duplex 2507, or 254 SMO. Sour service (H₂S) calls for Inconel, Monel, Hastelloy, or grades compliant with NACE MR0175. The final choice depends on the application, specify the fluid and conditions on the RFQ.
Are Crestflo fittings a drop-in replacement for Swagelok or Parker in hydraulic systems?
Yes. The parts interchange dimensionally, and that claim is backed by ASTM F1387 performance qualification. We call it interchange or equivalent, never "compatible" or "intermix." Ask our engineering team for your part-number cross-reference. Swagelok® and Parker® are trademarks of their respective owners; Crestflo isn't affiliated with either one.
Do you provide material traceability for hydraulic fittings?
Every part carries its own heat/lot number, with EN 10204 MTC 3.1 issued as standard and 3.2 on request. PMI comes with it too. Destructive testing at ISO/IEC 17025 laboratories backs up our in-house NDT, and we'll arrange third-party inspection on request.
What is the lead time for stainless or alloy hydraulic fittings?
Ready stock covers the standard items. Specials get made to order. Delivery usually runs 6 to 8 weeks, compared with the 20-plus weeks you'll wait with the major brands.
Do you supply valves and tubing for hydraulic circuits too?
Yes. We've got needle, ball, check/NRV, relief, metering, bleed and gauge-root valves, plus 2/3/5-valve manifolds. Monoflange and double-block-and-bleed valves are qualified to ASME B16.34, and we also carry stainless and alloy hydraulic tubing along with pressure snubbers.
Where are Crestflo hydraulic fittings made and are they TAA-compliant?
Standard product is of Indian origin with full material traceability; US / European melt is available on request where domestic-melt or TAA-eligible material is required. See the country-of-origin & compliance note for details.
Related Pages & Next Steps
Explore the tube fittings, DIN 2353 bite-type, high-pressure fittings and hydraulic tubing pages, the 316/316L and Duplex 2205 material pages, or the adjacent subsea and offshore industry pages and the full list of served industries. Ready to move: request a hydraulics RFQ, request a sample, or talk to an engineer.