TECTULby IMR

Fluid conveyance · Grooved flange adapters

TECHNICAL DATA SHEET

FT-TC-BRI-RAN-001

Issue date: August 5, 2026 · Rev. 001

Check the current version

Grooved system flange adapters — compatibility sheet: they mate only with Class 125/150 drilling, never Class 300

TECTUL · Dispatch across Colombia · Exports to Central & South America

Ductile iron flange adapters that solve in a single part the transition from a grooved system to flanged equipment: on one side they take the pipe groove per AWWA C606 and on the other they present a face with ANSI flange drilling. The TECTUL catalog publishes two references —grooved weld neck flange and grooved flat flange— from 1-1/2″ to 6″. This sheet is a compatibility sheet, not a calculation sheet, because the two decisions that make an order fail are about compatibility and not about strength: the adapter mates only with Class 125 or 150 drilling —never with a Class 300 valve or equipment— and its working pressure is set by the manufacturer's style, with a published industry range of 225 to 400 psi depending on brand, not by the AWWA C606 standard. The two data that can be tabulated precisely —the grooved pipe outside diameter by NPS and the Class 150 counter-flange bolt pattern— are in section 1.

SKU VT-86909 (grooved weld neck flange) · 2 references: weld neck (1-1/2″–4″) and flat (2″–6″) · sold by the unit

1. Technical specifications and compatibility table

What it is and what it solves

A grooved flange adapter is a transition part: at one end it has the geometry of the grooved system —it mounts over the groove machined into the pipe, with its gasket and coupling— and at the other it presents a flanged face with ANSI drilling to bolt to a valve, a pump, a strainer or a tank. Its value is in assembly: it lets you move from a grooved network, which is built without welding and comes apart in minutes, to a piece of equipment that only exists in a flanged version, without welding a flange to the pipe or cutting the line.

And its risk is compatibility. The grooved family has its own dimensional universe —the groove, the pipe's real outside diameter, the coupling style— and the flanged family has its own —the class, the bolt circle, the drilling—. The adapter sits on the border and that is why there are two ways to get it wrong that stay invisible until the part is on site: buying it for drilling other than the one it carries, and assuming a working pressure it does not declare. Both are in section 2.

Compatibility table by size

These are the two data that can be tabulated with standard precision: the steel pipe outside diameter over which the grooved side mounts, and the Class 150 counter-flange bolt pattern the flanged side mates with.

The pipe outside diameter is that of steel pipe per ASME B36.10M and does not change with schedule: that is why the grooved side is specified by NPS and groove type, not by schedule. The bolt pattern, circle and drilling are those of the ASME B16.5 Class 150 flange, identical to those of the counter-flange it bolts to (data sheet FT-TC-BRI-AC-001). What is not in this table —and is not published in the catalog— are the adapter body dimensions (length, thickness, neck height) and its bolting thread type: these belong to the manufacturer's style and are confirmed on quotation.

Groove dimensions are not in this sheet

The groove belongs to the pipe, not to the adapter: it is a geometry machined into the pipe (rolled or cut) whose dimensions —width, depth, distance from the end and tolerances— are set by AWWA C606 and published, within this series, by data sheet FT-TC-ACC-RAN-001 on grooved fittings. They are not repeated here. What must be declared when ordering is which groove type the installed pipe has —roll groove or cut groove— because they are not interchangeable and the gasket and coupling are chosen against that figure.

Material: ductile iron ASTM A536 grade 65-45-12

A ductile iron designation is its data sheet: the three numbers in "65-45-12" are, in that order, the minimum tensile in thousands of psi, the minimum yield in thousands of psi and the minimum elongation in per cent. It is the most used A536 grade in pipe fittings and the same one the grooved fittings family uses (data sheet FT-TC-ACC-RAN-001). The deciding figure is the 12 % elongation: that is what makes this material deform before breaking, unlike grey cast iron, which is brittle and not admitted in pressure components of this kind. The catalog does not declare the material of these two references: the real grade is confirmed on quotation.

The catalog's 2 references

The two references cover different ranges: only the weld neck reaches 1-1/2″ and only the flat reaches 6″. Between 2″ and 4″ both are available and the choice is one of assembly, not of strength — see section 3.

General specifications

2. Compatibility sheet: the four data and the three warnings

The four data that define the order

This sheet carries no calculation section because the adapter is not sized: it is matched. The four data you must have before ordering, in order of how many orders each one ruins:

Warning 1: it mates only with Class 125/150 — never with Class 300

This is the incompatibility no Spanish-language sheet underlines and the one that sends back the most material. A grooved flange adapter is made with the drilling of the ANSI Class 125 (cast iron) or Class 150 (steel) flange, which share a bolt pattern, and with no other. Against a Class 300 valve, pump or strainer there is no way to bolt it, and the reason is geometric, not one of strength:

From 2″ up the hole count already differs between the two classes, so the mistake is discovered when the part is presented. Between 1/2″ and 1-1/4″ both classes have 4 holes and only the bolt circle changes by a few millimetres: there the mistake is more treacherous, because it "almost fits". If the equipment on the other side is Class 300, the answer is not to force the grooved adapter: it is to install a Class 300 flange welded or threaded to the pipe (data sheet FT-TC-BRI-AC-001) and give up the grooved joint at that point.

Warning 2: the working pressure belongs to the style, not to the standard

AWWA C606 standardizes the geometry of the grooved joint —groove dimensions, tolerances, joint requirements— but it does not assign a working pressure to a flange adapter. That number is declared by the manufacturer for its specific style, and the range found published in industry style sheets runs from 225 to 400 psi (15.5 to 27.6 bar) by brand and size: a spread of nearly twofold between the low and the high end.

The design consequence is direct: you cannot specify "grooved flange adapter, AWWA C606" and take a pressure for granted. You must specify the style or require the rating in writing. And the purchasing consequence too: two adapters of the same size that look identical may have ratings 175 psi apart. That is why in this sheet the supplied product's working pressure is declared as a figure to confirm on quotation, not published as our own.

Warning 3: imported units may carry metric bolting

A purchasing detail that appears on no data sheet and does appear on site: imported "grooved type" adapters are published with metric bolting —M16, M20, M24— instead of the ASME B16.5 inch series. An M16 bolt is not a 5/8″ and an M20 is not a 3/4″: they are different diameters, with different threads and different nuts. If the joint is assembled with the bolting supplied with the adapter there is no problem; the problem appears when a bolt is lost and replaced with whatever is in the store, or when the bolting is quoted separately against the inch stud table. Check the thread of the supplied adapter before quoting its bolting.

3. Weld neck or flat, fire protection and assembly order

Weld neck or flat: the choice is one of assembly

Neither withstands more pressure than the other because of its shape: the rating is set by the manufacturer's style, the same in both. The choice is made by available space, by alignment and by the size needed — and at 1-1/2″ and 6″ there is no choice, because there is only one reference.

Why this part lives in fire protection networks

The grooved system is the assembly standard for fire protection networks for a practical reason: a sprinkler network is long, branched and installed in false ceilings and tight spaces, and a grooved joint is built without welding, without sparks, without a hot work permit, and comes apart for maintenance in minutes. In that context the flange adapter is the part that connects the network to whatever is flanged: the OS&Y gate valve, the indicating butterfly valve, the strainer, the fire pump and its header.

Hence the requirement to verify in this market: in fire protection, components are usually required with UL listing or FM approval of the supplied style. That certification belongs to the manufacturer's style, just like the pressure rating, and cannot be inferred from AWWA C606: it is requested in writing. The TECTUL catalog's fire protection family groups the remaining components of that line.

The assembly mistake characteristic of this part

It is a sequencing mistake, not a selection one: tightening the bolted joint before the grooved coupling is fully seated. The grooved side has assembly clearance by design —that is what gives the joint its angular flexibility— and if the flange is tightened first, that clearance is taken up unevenly and the coupling gasket ends up loaded to one side. The correct order is the reverse: first seat and tighten the grooved coupling to its style's torque, then bolt the flange in a star pattern in passes (ASME PCC-1-2022). And one check that saves a disassembly: verify that the adapter's flanged face is parallel to the equipment's before inserting the first stud.

4. Frequently asked questions

Will a grooved flange adapter do for a Class 300 valve?

No. The adapter is made with the drilling of the ANSI Class 125 or 150 flange and with no other, and against a Class 300 neither the bolt circle nor the hole count match. At 3″, for instance, Class 150 has 4 holes of 19.1 mm on a 152.4 mm circle and Class 300 has 8 holes of 22.4 mm on a 168.3 mm circle: there is no way to bolt them together. If the equipment on the other side is Class 300, you must give up the grooved joint at that point and install a Class 300 flange welded or threaded to the pipe.

How much pressure does a grooved flange adapter withstand?

Whatever the manufacturer's style declares, and that is the complete answer: AWWA C606 standardizes the geometry of the grooved joint but assigns no working pressure to this part. The range published in industry style sheets runs from 225 to 400 psi (15.5 to 27.6 bar) by brand and size — nearly twofold from one end to the other. Two adapters of the same size that look identical may differ by 175 psi, so the supplied product's rating is requested in writing and confirmed on quotation.

What do I need to know before ordering one?

Four data: (1) the class of the flanged equipment on the other side —if it is 300, the adapter will not do—; (2) the real outside diameter of the grooved pipe, measured, because there is imported pipe with metric diameters that match no NPS; (3) the groove type of the pipe, rolled or cut, which are not interchangeable; and (4) the adapter's style and rating. With those four the order will not fail; without the first, the part gets returned.

What is the difference between the grooved weld neck flange and the flat one?

The neck and the size range, not the strength. The weld neck gains usable length and eases alignment correction; the flat bears directly against the equipment face and is the typical transition to a butterfly valve, a strainer or a pump. Both carry ANSI Class 125/150 drilling and both are ductile iron, so their rating is equally set by the manufacturer's style. In the TECTUL catalog only the weld neck is published in 1-1/2″ and only the flat reaches 6″: at those two sizes there is no choice.

Where are the groove dimensions?

In data sheet FT-TC-ACC-RAN-001 on grooved fittings, and they are not repeated here because the groove belongs to the pipe, not to the adapter: it is a geometry machined into the pipe (width, depth, distance from the end and tolerances) set by ANSI/AWWA C606. What must be declared when ordering the adapter is the groove type: roll groove or cut groove.

Is the adapter's bolting in inches?

Not necessarily. Imported adapters are frequently published with metric bolting —M16, M20, M24— instead of the ASME B16.5 inch series, and an M16 is not a 5/8″ nor an M20 a 3/4″: diameter, thread and nut all differ. As long as the bolting supplied with the part is used there is no problem; the problem appears when replacing a bolt with whatever is in the store or when quoting the bolting separately against the inch stud table in data sheet FT-TC-BRI-ESP-001. Check the thread of the supplied adapter.

Why is it used so much in fire protection networks?

Because the grooved system is the assembly standard for those networks: it is built without welding, without sparks, without a hot work permit, and comes apart for maintenance in minutes, which in false ceilings and tight spaces decides the project. The flange adapter is the part that connects that network to components that only exist flanged: the OS&Y gate valve, the indicating butterfly valve, the strainer and the pump. In that market UL listing or FM approval of the supplied style is usually also required, which cannot be inferred from AWWA C606 and is requested in writing.

Is the flange or the grooved coupling tightened first?

The grooved coupling first, to its style's torque, and the flange afterwards in a star pattern in passes. The grooved side has assembly clearance by design —that is what gives the joint its angular flexibility—: if the flange is tightened first, that clearance is taken up unevenly and the coupling gasket ends up loaded to one side. And before inserting the first stud, check that the adapter's flanged face has ended up parallel to the equipment's.

5. Application notes

6. Technical notice and limitation of liability