Stainless Steel Conical Unions
A stainless taper seat union is an AISI 304 fitting that joins two stainless pipes, or a pipe and equipment, detachably and seals without a gasket through its taper metal-to-metal seat.
It allows removal without cutting the line during maintenance of process pumps, filters, heat exchangers and instruments. As there is no gasket, no chemically resistant gasket has to be selected; sizes from 1/8″ to 4″ are available.
Main Applications
- Process pump inlet-outlet connections
- Filter and strainer removal
- Heat exchanger and tank connections
- Instrument and flowmeter separation
- Points removed for cleaning in food lines
- Chemical dosing groups
Technical Data
| Fitting type | Taper seat union: two bodies and a nut |
|---|---|
| Product standard | ISO 4144 (manufacturer sheet) |
| Material | AISI 304; AISI 316 in a selected size (product range) |
| Thread | ISO 7-1 Rp female thread; nut thread ISO 228-1 (depending on model) |
| Seat | Taper, metal-to-metal; no gasket |
| AISI 304 sizes | 1/8″, 1/4″, 3/8″, 1/2″, 3/4″, 1″, 1 1/4″, 1 1/2″, 2 1/2″, 3″, 4″ (product range) |
| AISI 316 size | 1/8″ (product range) |
| Pressure, −20 … +38 °C | 20 bar (ISO 4144 Table 2, manufacturer sheet) |
| Pressure, 100 °C | 16.5 bar (ISO 4144 Table 2, manufacturer sheet) |
| Pressure, 150 °C | 15 bar (ISO 4144 Table 2, manufacturer sheet) |
| 2″ size | Please ask |
| Surface | Stainless, uncoated |
Material Options
| Part | AISI 304 stainless | AISI 316 stainless | Galvanized malleable iron |
|---|---|---|---|
| Body (two pieces) | AISI 304 (cast equivalent 1.4308 / CF8, depending on model) | AISI 316 (cast equivalent 1.4408 / CF8M, depending on model) | Malleable iron EN-GJMB-350-10, galvanized |
| Nut | AISI 304 stainless | AISI 316 stainless, depending on model | Zinc-coated malleable iron |
| Seat surface | Taper metal-to-metal | Taper metal-to-metal | Taper metal-to-metal |
| Surface | Uncoated stainless | Uncoated stainless | Zinc coated |
| Pressure rating | 20 bar −20…+38 °C (ISO 4144) | 20 bar −20…+38 °C (ISO 4144) | 25 bar −20…120 °C (EN 10242) |
Which material? Since there is no gasket, no gasket material compatible with the medium is needed; only the body grade, 304 or 316, is chosen for the medium.
Advantages
No Gasket Compatibility Issues
- No gasket selection needed for chemical media
Fast Removal for Cleaning
- Opening the nut separates the equipment from the line
Retightenable
- The taper face is reused after maintenance
Stainless Nut
- Body and nut in the same material
Construction and Design Features
- Two bodies with male and female taper faces and a hexagonal nut
- Parallel nut thread (ISO 228-1, depending on model)
- Uncoated stainless parts
- ISO 4144 pressure ratings
Send the union size, grade and quantity; we will confirm the lead time for sizes not shown in stock, such as 2″.
How to Choose?
- Define removal pointsPlan a union at every piece of equipment that needs maintenance, such as pumps, filters and instruments.
- Choose the gradeChoose a 304 or 316 body for the medium; no gasket selection is needed.
- Measure the sizeDetermine the pipe size; ask for stock of 2″.
- Watch the tighteningOvertightening stainless threads causes galling; use a suitable lubricant.
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Details →Get a quote for your project
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