EKINSUN LTD is a custom parts manufacturer that machines pump fittings to drawing: an outlet adapter from a G3/8 pump port to a 1/2 NPT line, an MFF tee with a G1/4 gauge branch, an extension that brings the outlet clear of the motor, an inlet barb for an odd hose, a replacement connector measured from the broken one, from 1 piece in brass, 304 or 316L; standard pump fittings in one standard are catalogue parts. Pumps themselves are catalogue products chosen by flow, pressure, voltage and port, and are sourced as such when a replacement is part of the job; the connections are what is machined.
A typical request: a vane pump outlet G3/8, a gauge G1/4, a regulator G1/2 female both ends, and a 10 mm push-in line — four parts, three of them off the shelf, and the tee is the one that is not.
The tee that has to carry three of those threads at once is the pump fitting most often machined.
The outlet chain, port by port
| Position | Fitting | Threads involved | Catalogue or machined |
|---|---|---|---|
| Pump outlet port | adapter or nipple into the port | pump port G3/8, G1/2, NPT or metric | catalogue in one standard; machined across standards |
| Branch point | MFF tee: male into the port, female onward, female branch | pump port × line × G1/4 or 1/4 NPT gauge branch | machined when the three differ — threaded tees |
| Pressure monitoring | gauge adapter, glycerin-filled gauge on a vibrating pump | G1/4, G1/8, 1/4 NPT, M20×1.5 | catalogue or machined — gauge adapters |
| Pressure control | regulator or bypass valve connection | G1/4–G1/2 female on the valve | catalogue or machined — valve fittings |
| Direction control | check valve on the outlet | G1/4–G1/2; push-in | series or machined body — check valves |
| Routing | 90° street elbow | one or two standards | catalogue in one standard; machined mixed — threaded elbows |
| Tube connection | push-in or compression fitting | thread × 6, 6.35, 8, 10, 14 mm tube | series — push-in or compression |
| Inlet (suction) | hose barb, strainer, inlet adapter | pump inlet port × hose ID | catalogue or machined — hose barbs |
Need pump fittings and pump adapters in a size, thread or material no catalogue lists? EKINSUN is a custom parts manufacturer: we make pump fittings and pump adapters to your drawing, sketch or sample — brass, 304 or 316L stainless steel — from 1 piece, quoted in 12 hours and shipped duties paid. If the size is standard, ask anyway — it may be in stock, and the unit price drops as the quantity rises. All custom adapters and fittings →
Pump ports: what to measure
| Pump | Usual ports | Measure on the pump |
|---|---|---|
| Rotary vane pump, small (beverage, water, chemical dosing) | G3/8 or G1/2 female; some NPT | thread diameter and pitch at the port mouth; parallel or tapered; face flat or with a seat |
| Gear pump | G1/4–G1 female; SAE flange on larger units | port thread; flange bolt pattern if flanged |
| Diaphragm pump | G1/4–G3/4; push-in or barb on small units | port thread or barb OD |
| Dosing and metering pump | G1/4, G3/8; 6–10 mm tube unions | tube OD and union thread |
| Coolant pump (machine tool) | G3/8–G1-1/4 female; flange | port thread; flange |
| Vacuum pump | G1/4–G1; KF flange | thread or KF size — vacuum flange adapters |
| Old pump with a connector nobody sells | unknown | the connector, or the pump port it left behind, with a caliper |
Identify the thread before you order the pump adapter. Measure the outside diameter of a male thread, or the inside diameter at the mouth of a female one, with a caliper, and count the threads in 25 mm or in one inch. A G1/4 male measures about 13.2 mm across and has 19 threads per inch; a 1/4 NPT male measures about 13.7 mm and has 18; an M14×1.5 measures 14.0 mm with 1.5 mm between crests. Those three are the ones most often confused on a fitting, and only the metric one is not tapered. Then check whether the thread is parallel or tapered by measuring the diameter at the first and the fifth turn. The fitting thread identification chart lists every common pipe, port and tube thread with its diameter, pitch and seal, and the BSPP vs BSPT note explains the parallel and taper forms of the same BSP size.
What to send for a pump fitting that is not catalogued
- The pump port: thread standard, size and pitch, or a photo of the port with a caliper across it; inlet or outlet.
- The line: pipe thread, tube outside diameter or hose inside diameter.
- What else must connect at the outlet: gauge (its thread), regulator or valve (its ports), check valve, elbow.
- Medium, pressure and temperature, so seals and materials are right.
- For a replacement: the old connector, broken or not, or the pump nameplate and a photo of the port.
- Quantity: from 1 piece.
Where the pump fitting catalogue stops
| What you need | In the catalogue? | What we make |
|---|---|---|
| A nipple, reducer, elbow, tee, barb or tube fitting in the pump port's own standard and size | Yes | Buy it from stock, or have it made to order from 1 piece; no one-off competes on price with a catalogue fitting. Standard parts: ask us too — we may have them in stock. |
| A gauge, regulator or check valve with catalogue ports | Yes | Buy them as catalogue products; their ratings come from their makers. Standard parts: ask us too — we may have them in stock. |
| An outlet adapter from a G pump port to an NPT or metric line, or the reverse | No | Machined from hex bar, each end to its own standard, from 1 piece. |
| An MFF tee whose three ports are not one standard and size | No | Machined from square bar. |
| An extension, offset or elbow of a length that clears the motor, the base or a guard | No | Machined to the drawing. |
| An inlet barb or strainer adapter for an odd hose or a metric port | No | Machined; barb to the hose ID. |
| A connector from an obsolete pump, reproduced from the old part or from the port it fits | No | Measured and machined — see replacement fittings from a sample. |
| A pump fitting in 316L, titanium, PEEK or aluminium 6061 / 7075 | No | Same geometry, your material; aluminium for vacuum and air pumps. |
Materials
| Material | Designation | Where it fits here |
|---|---|---|
| Brass | CW614N / C36000 machined; CW617N forged forms | water, beverage and oil pump connections; nickel plated on request |
| Stainless 304 | 1.4301 | standard stainless fittings; general chemical and washdown |
| Stainless 316L | 1.4404 | chemical dosing, marine and food-plant pumps |
| Free-machining stainless | 303 / 1.4305 | custom turned adapters where corrosion duty allows |
| Carbon steel | zinc or phosphate | hydraulic and coolant pump connections |
| Aluminium 6061 | AlMg1SiCu | vacuum and air pump adapters, anodised |
| Aluminium 7075 | AlZn5.5MgCu | machined pump manifolds |
| PEEK, PVDF, PP | PEEK; PVDF; PP | chemical dosing pump connections |
Related pages
- the adapter, elbow and tee chart — every fitting form by ports and standard
- MFF and FFF tees — the MFF tee on the outlet
- Pressure gauge adapters — the gauge connection
- valve inlet and outlet adapters — regulator and bypass connections
- pneumatic check valves — the check valve on the outlet
- Hose barb adapters — suction hoses
- obsolete fittings reproduced — obsolete pump connectors
- brass nipples, elbows and tees — brass forms for pump water lines
- Reverse engineering — obsolete pump parts beyond the fittings
Frequently asked questions
A 3/8 in BSP parallel thread, about 16.7 mm across with 19 threads per inch, the common port on small rotary vane and gear pumps in Europe. It seals on the face with a washer or O-ring, and it does not mate with 3/8 NPT, which is tapered and 18 threads per inch.
An adapter or nipple into the port, a tee with a gauge branch, a regulator or bypass connection, sometimes a check valve, an elbow to turn the line and a push-in or compression tube fitting. Each is a catalogue part when it matches the pump port standard; the tee is the part most often machined because it carries three threads at once.
Yes. An adapter with the metric fine thread on the pump side and G, NPT or a tube fitting on the line side is machined in brass or stainless, from 1 piece, with a face seal on the metric end.
Yes. The old connector, even broken, or the pump port it fits is measured, the thread identified, and the fitting machined in brass, 304 or 316L; a drawing goes back for approval before machining.
EKINSUN LTD is a custom parts manufacturer that machines inlet and outlet adapters, gauge tees, extensions, elbows and barbs for rotary vane, gear, diaphragm, dosing, coolant and vacuum pumps in brass, 304 / 316L stainless, steel, aluminium and PEEK, from 1 piece, with a quote within 12 hours.
No list price; the drivers are material, the number of threads, length, any branch, and quantity. A brass outlet adapter in two standards is a short lathe job; a 316L MFF tee with a gauge branch is a milled and drilled part and priced as one. Where a standard fitting in the chain would do, the quote says so.
Send the pump port and the line
Pump type, inlet or outlet, port thread or a photo with a caliper, line end (thread, tube OD, hose ID), gauge and valve threads, medium, quantity; for a replacement the old connector or the nameplate. From 1 piece, quote within 12 hours.
Not sure of the thread? Tell us four things: what the fitting connects to (pump, valve, gauge, cylinder, tube or hose); whether the port is the inlet or the outlet; which way the flow must go; and the tube outside diameter, not the hose bore, unless it is a barb. A photo with a caliper across the thread answers most of it.