Stainless Steel Grooved Fittings
DN25 – DN300 · ANSI / AWWA C606 · ISO 6182-12 · 300 – 700 psi
Grooving (roll- or cut-groove) plus a coupling and gasket gives fast mechanical joining of stainless steel pipe, replacing welding, threading and flanging. Coupling and flange-adapter bodies are 316 stainless (ASTM A351 / A743 / A744 CF8M). Grooved-end fittings are supplied in 304 / 316 / 316L (cast CF8 / CF8M, or welded to ASTM A312) and fit 304 / 304L / 316 / 316L austenitic stainless pipe.
STANDARD
AWWA C606 · ANSI B16.9
SIZE RANGE
1″–12″ · DN25–300 (couplings to 18″ / AGS to 24″)
MATERIAL
316 (CF8M) · 304 / 316 / 316L
PRESSURE
275–700 psi (by type and wall thickness)
Product Range
The complete grooved mechanical jointing system: couplings, grooved-end fittings, flange adapters and branch outlets.
Couplings — Rigid & Flexible
Rigid Style 489: 1½–12″ · 600 psi · Light-duty flexible Style 475: 1–4″ · 500 psi · Flexible Style 77S: 8–18″ · 300 psi · AGS rigid W89: 14–24″ · 700 psi
Elbows
90° and 45°, long and short radius · cast 1–8″ and welded Sch.10 / Sch.40 · types SS-10 / SS-11 / 7050SS
Tees
Equal, reducing and side-outlet tees · 1–12″ (DN25–300)
Crosses
Equal and reducing crosses
Caps & Plugs
Grooved-end closure · 1–12″
Reducers
Concentric and eccentric · 2×1 up to 12×10
Flange Adapters
Style 441: 2–6″ (DN50–150) · 275 psi · ANSI Class 150 raised face
Mechanical Tees & Crosses
Hole-cut clamp branch · main line 2–12″ · standard, threaded or flanged outlet
Category Overview
Working pressure varies with pipe material, wall thickness and size; the table lists the maximum rating of each type.
| Category | Typical Type | Connection | Material | Size Range |
|---|---|---|---|---|
| Rigid coupling | Style 489 | Groove × Groove | 316 (CF8M) | 1½–12″ / DN40–300 |
| Flexible coupling | Style 475 / 77S | Groove × Groove | 316 (CF8M) | 1–18″ / DN25–450 |
| Flange adapter | Style 441 | Groove × Flange | 316 (CF8M) | 2–6″ / DN50–150 |
| AGS rigid coupling | Style W89 | Groove × Groove | Stainless steel | 14–24″ / DN350–600 |
| 90° / 45° elbow | SS-10 / SS-11 / 7050SS | Groove × Groove | 304 / 316 / 316L | 1–12″ / DN25–300 |
| Equal tee | SS series tee | Groove × Groove × Groove | 304 / 316 / 316L | 1–12″ / DN25–300 |
| Reducing tee | SS series reducing tee | Groove (one end reduced) | 304 / 316 / 316L | 2×2×1 to 12×12×8 |
| Reducer | Concentric / eccentric | Groove × Groove | 304 / 316 / 316L | 2×1 to 12×10 |
| Cap | Grooved cap | Grooved end closure | 304 / 316 / 316L | 1–12″ |
| Mechanical tee / cross | Hole-cut branch fitting | Groove + clamp hole cut | 304 / 316 | Main line 2–12″ |
Gasket Temperature Ratings
Common to the grooved coupling range — select the grade by service medium.
| Gasket Grade | Material | Colour Code | Temperature Range | Service |
|---|---|---|---|---|
| Grade E | EPDM | Green stripe | –34 to +110 °C | Cold and hot water, dilute acids, oil-free air, many chemicals |
| Grade EW | EPDM | Green “W” | –34 to +110 °C | Hot and cold water (WRAS / BS 6920; potable hot water ≤ +65 °C) |
| Grade T | Nitrile NBR | Orange stripe | –29 to +82 °C | Petroleum products, hydrocarbon-laden air, vegetable and mineral oils |
| Grade O | Fluoroelastomer FKM | Blue stripe | –7 to +149 °C | Oxidising acids, petroleum, halogenated hydrocarbons, hydraulic oil, organic fluids |
| Grade L | Silicone | Red stripe | –34 to +177 °C | Dry heat, hydrocarbon-free air, selected chemicals |
Bolts, Nuts & Installation Torque
Torque figures are tabulated values; tighten alternately and evenly across the joint.
| Model | Size Range | Nut Size | Socket Size | Torque Requirement |
|---|---|---|---|---|
| Style 489 | 1½″–2½″ | — | — | 18 ft-lbs / 25 N·m |
| Style 489 | 3″–4″ | 5/8″ / M16 | 1 1/16″ / 27 mm | 45 ft-lbs / 61 N·m |
| Style 489 | 139.7 mm | 3/4″ / M20 | 1 1/4″ / 32 mm | 75–100 ft-lbs / 100–137 N·m |
| Style 489 | 5″–12″ | 7/8″–1″ / M22–M24 | 1 7/16″–1 5/8″ / 36–41 mm | 85–200 ft-lbs / 115–275 N·m |
| Style 475 | ¾″–2½″ | 3/8″ / M10 | 11/16″ / 17 mm | Until metal-to-metal contact |
| Style 475 | 3″–4″ | 1/2″ / M12 | 7/8″ / 22 mm | Until metal-to-metal contact |
| Style 475 | 5″–12″ | 5/8″ / M16 | 1 1/16″ / 27 mm | Until metal-to-metal contact |
| Style 77S | 8″–18″ | 7/8″–1 1/8″ / M22–M27 | 1 7/16″–1 13/16″ / 36–46 mm | Until metal-to-metal contact |
| Style W89 | 14″–24″ | 1 1/8″ / M27 | 1 13/16″ / 46 mm | See product marking |
Installation notes
Installation: tighten all coupling nuts alternately and evenly until the bolt pads reach metal-to-metal contact; apply anti-seize compound to stainless fasteners before assembly. For flange adapters the flat-face flange must be machined flat — do not use it as a tie-rod anchoring point, and do not install against wafer-type valves.
Installation: tighten all coupling nuts alternately and evenly until the bolt pads reach metal-to-metal contact; apply anti-seize compound to stainless fasteners before assembly. For flange adapters the flat-face flange must be machined flat — do not use it as a tie-rod anchoring point, and do not install against wafer-type valves.
MTC
EN 10204 3.1 mill test certificate with every shipment
Chemical composition and mechanical properties are reported with measured values, with full heat-number traceability back to the original coil certificate.
Frequently Asked Questions
What is the difference between rigid and flexible grooved couplings?
Rigid couplings lock the pipe ends together and prevent movement — used where no differential movement is required. Flexible couplings allow limited axial expansion and angular deflection, which suits seismic, thermal-movement or vibration-prone systems.
Which standards do your grooved fittings meet?
ANSI / AWWA C606 for grooved and shouldered joints, and ISO 6182-12 for fire-protection couplings. Gasket grades are selected for potable, industrial or fire service.
What size range do you cover?
DN25 – DN300, covering rigid and flexible couplings, 90° and 45° elbows, tees, reducers, crosses, caps, mechanical tees and flange adapters.
Which gasket materials are available?
EPDM for general water service, Nitrile for oil, Silicone for high temperature and FKM / Viton for aggressive chemicals. A graded service guide is available for each application.
How do I select the right coupling size?
Grooved couplings are matched to the pipe outside diameter, not the nominal size. Send your pipe OD and wall thickness — or the standard you follow — and we confirm the match.
Request a Quote
A formal quotation lands in your inbox within 12 working hours.
- Quotation with dimension table and material certificates
- MOQ, lead time, packing and Incoterms 2020
- Free samples of standard sizes (courier collect)
- EN 10204 3.1 MTC with every shipment