EKINSUN LTD is a custom parts manufacturer that machines valve adapters to drawing: a G1/2 male to 1/2 NPT female connector for a pressure reducing valve on US pipe, an M22×1.5 to G3/8 adapter for a solenoid valve on a hydraulic port, a street elbow out of a ball valve into a hose barb, an extension that lifts a relief valve clear of insulation, a gauge tee on a regulator outlet, from 1 piece in brass, 304 or 316L; standard valve fittings in one standard are catalogue parts.
A typical request: a DN15 pressure reducing valve with G1/2 female both ends going into a building piped in 1/2 NPT — two adapters, and nobody stocks G to NPT in the same size.
Same size, two standards, is the valve adapter we machine most; a metric port on a solenoid valve is the second.
The ports valves usually have
| Valve | Usual ports | Sizes | Note |
|---|---|---|---|
| Ball valve, threaded | F × F, G (BSP) in Europe, NPT in the US | G1/4–G2; NPT 1/4–2 | DN15 = G1/2, DN20 = G3/4, DN25 = G1 |
| Needle valve | F × F or M × F | G1/8–G1/2; NPT 1/8–1/2; 1/4 in tube | instrument and sampling lines |
| Solenoid valve | F × F | G1/8, G1/4, G3/8, G1/2; NPT | port size in the valve code; metric ports on some hydraulic valves |
| Pressure reducing valve (water) | F × F | G1/2–G2 (DN15–DN50) | often union ends |
| Pressure regulator (air, gas) | F × F, gauge port F | G1/4, G3/8, G1/2; gauge G1/8 or G1/4 | the gauge port is a second connection to adapt |
| Relief and safety valve | M inlet, F or M outlet | G1/4–G1; NPT | inlet thread into the vessel or block |
| Check valve | M × F, F × F | G1/8–G1/2; NPT | see pneumatic check valves |
| Gauge valve, gauge cock | M × F | G1/4 or 1/2 NPT to the gauge | see gauge adapters |
| Cartridge valve, manifold-mount | SAE ORB or metric cavity | SAE -8, -10, -12; M18–M27 | the manifold, not the valve, carries the ports |
DN is the nominal bore in millimetres and maps to BSP nominal sizes: DN15 = 1/2 in, DN20 = 3/4 in, DN25 = 1 in, DN32 = 1-1/4 in, DN40 = 1-1/2 in, DN50 = 2 in.
Need valve fittings and valve adapters in a size, thread or material no catalogue lists? EKINSUN is a custom parts manufacturer: we make valve fittings and valve adapters to your drawing, sketch or sample — brass, 304 or 316L stainless steel — from 1 piece, quoted in 12 hours and shipped duties paid. Already a catalogue size? Ask us too — we may have it in stock, and larger quantities cost less per piece. All custom adapters and fittings →
Port to line: which fitting
| Valve port | Line | Fitting | Catalogue or machined |
|---|---|---|---|
| G1/2 female | G1/2 male pipe | none, or a nipple | catalogue |
| G1/2 female | 1/2 NPT pipe | G1/2 male × 1/2 NPT female adapter | machined (same size, two standards) |
| G1/2 female | G3/8 line | G1/2 male × G3/8 female reducer | catalogue in brass and 304 |
| G1/4 female | 8 mm push-in tube | male stud push-in fitting G1/4 × 8 mm | catalogue — push-in fittings |
| G1/4 female | 6 mm tube with M12×1.5 on the other device | machined stud body | machined |
| M22×1.5 female (hydraulic solenoid) | G3/8 line | M22×1.5 male × G3/8 female adapter | machined |
| G1/2 female, valve behind insulation | G1/2 pipe | G1/2 extension nipple, 60–150 mm | machined to length |
| G3/4 female ball valve | 1 in hose | G3/4 male hose barb for 25 mm hose | catalogue or machined — hose barbs |
| G1/4 gauge port on a regulator | 1/4 NPT gauge | G1/4 male × 1/4 NPT female gauge adapter | machined |
| Any port, line at 90° | same or other size | street elbow | catalogue in one standard; machined mixed — threaded elbows |
A G1/2 pressure reducing valve on four different lines — worked example
A DN15 pressure reducing valve has G1/2 female ports at both ends and is sold that way in every catalogue; the line it goes into is decided by the building or the machine, not by the valve. The first table is the valve in the photograph, as specified by the supplier; the second is what joins it to each line. The valve body is never re-threaded: the fitting takes the difference.
| Feature | Value |
|---|---|
| Ports | G1/2 female inlet and outlet, ISO 228 parallel (DN15); flat port faces, hex on each port |
| Body | nickel-plated brass; knurled cap over the adjusting screw, plug at the bottom |
| Working principle | compensated piston — the outlet setting holds as the inlet pressure changes |
| Inlet pressure | up to 20 bar |
| Outlet setting | 1–7 bar, set at 3 bar as delivered |
| Temperature | 0–80 °C |
| Media | water, compressed air, glycol solutions |
| Gauge port | none — a gauge needs a branch on the outlet side |
| Line | Fitting on the valve port | Catalogue or machined |
|---|---|---|
| Inlet on 1/2 NPT pipe (US, Canada) | G1/2 male × 1/2 NPT male hex nipple — the G end with a shoulder and washer face for the valve’s flat port | machined, same size two standards |
| Outlet on 15 mm copper (UK) | G1/2 male × 15 mm compression | catalogue |
| Outlet on a machine port M22×1.5 | G1/2 male × M22×1.5 male, or female | machined |
| A gauge on a valve that has no gauge port | G1/2 female × G1/2 male with a G1/4 side port drilled and tapped, or a G1/2 × G1/4 gauge tee | machined; the tee is catalogue |
| Valve in a G3/4 line | G3/4 male × G1/2 male reducing nipples, one each side | catalogue |
| Compressed-air line to a 1/4 NPT tool hose | G1/2 male × 1/4 NPT female reducer | machined, two standards |
| Valve set back behind a panel or insulation | G1/2 extension nipples, 60–150 mm | machined to length |
| Stainless or marine line, glycol at low temperature | the same adapters in 316L (1.4404) | machined |
Two of the eight rows are catalogue parts; the other six are machined from hex bar, each end to its own standard, from 1 piece. The G end of every adapter that screws into this valve seals on a washer at its shoulder against the flat port face, the NPT end on its taper with tape, the M22×1.5 end on an O-ring or a bonded seal. A body for this valve type in 316L, or with the G1/4 gauge boss this one lacks, is quoted as a machined part for an equipment builder; the piston, seat and spring stay the valve maker’s — see custom valve bodies.
What to send for a valve fitting that is not catalogued
- The valve port: male or female, standard, size and pitch; the valve type and its nominal size (DN) if the thread is unknown.
- The line: pipe thread, tube outside diameter, or hose inside diameter, and its standard.
- The path: straight, 90°, a length to clear something, a gauge or drain branch.
- Material and seal: brass for water and air, 304 / 316L for chemical and marine; O-ring, bonded washer, PTFE tape or a machined seat.
- Medium, pressure and temperature, so the seal is right; quantity.
Identify the thread before you order the valve 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.
Where the valve fitting catalogue stops
| What you need | In the catalogue? | What we make |
|---|---|---|
| A nipple, reducer, street elbow or hose barb in one standard, inside the standard sizes | 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 push-in or compression stud in a series thread on a valve port | Yes | Standard sizes: buy it off the shelf, or have it made to order from 1 piece. Standard parts: ask us too — we may have them in stock. |
| Same size, two standards — G1/2 to 1/2 NPT, G3/8 to 3/8 NPT, R to NPT | No | Machined from hex bar, each end to its own standard, from 1 piece. |
| A metric port on a solenoid or hydraulic valve to a G or NPT line | No | Machined; the metric fine thread single-pointed. |
| An extension nipple or adapter of a length that clears insulation, a housing or a bracket | No | Machined to length. |
| A gauge, drain or vent branch on a valve inlet or outlet | No | Machined as a tee or a drilled adapter — see threaded tees. |
| A valve adapter in 316L, titanium, PEEK or aluminium 6061 / 7075 | No | Same geometry, your material; aluminium for air and vacuum valves. |
| A pressure reducing valve body in 316L, or with a gauge boss the standard body lacks | Partly | Machined to drawing as a body for an equipment builder, internals from the valve maker; no pressure rating is claimed for a machined body, and we say so before quoting. |
| The valve itself in a special port | Partly | Standard valves come with their catalogue ports; special ports are adapted with a machined fitting rather than by modifying the valve body, and we say so. |
Materials
| Material | Designation | Where it fits here |
|---|---|---|
| Brass | CW614N / C36000 machined; CW617N forged forms | valve adapters for water, air and oil; nickel plated on request |
| Stainless 304 | 1.4301 | standard stainless nipples and reducers; machined adapters |
| Stainless 316L | 1.4404 | chemical, marine and food-plant valve connections |
| Free-machining stainless | 303 / 1.4305 | custom turned adapters where corrosion duty allows |
| Carbon steel | zinc or phosphate; A105 forged | hydraulic and steam valve connections |
| Aluminium 6061 | AlMg1SiCu | air and vacuum valve adapters, anodised |
| Aluminium 7075 | AlZn5.5MgCu | machined valve manifolds |
| PEEK, PVDF | PEEK; PVDF | chemical valve adapters |
A real job of this kind: A Precision Aluminium Hydraulic Valve Body — an aluminium hydraulic valve body with intersecting passages and BSP/NPT ports square to their seats.
Related pages
- every fitting by port combination — every fitting form by ports and standard
- one-way valve fittings — one-way valves and their adapters
- pump inlet and outlet adapters — the valve on the pump outlet
- Pressure gauge adapters — the gauge on the regulator
- BSP to NPT adapters — the same-size, two-standard adapter
- street elbows and 90° adapters — street elbows out of valve ports
- Metric to imperial adapters — metric valve ports on G or NPT lines
- fittings copied from the broken part — connectors for valves nobody makes any more
- G, R, NPT and metric by diameter and pitch — G, R, NPT and metric by diameter and pitch
Frequently asked questions
G1/2 (BSP 1/2 in) in Europe, where DN15 means a 15 mm nominal bore; the same size in the US is 1/2 NPT. DN20 is G3/4 or 3/4 NPT, DN25 is G1 or 1 NPT. A G1/2 and a 1/2 NPT thread are almost the same diameter and do not mate.
With a G1/2 male × 1/2 NPT female adapter on each port, or the reverse genders. Same-size, two-standard adapters are not a catalogue item and are machined from hex bar with each end to its own standard, from 1 piece.
Yes, with a machined adapter: the metric fine thread on the valve side and the G or NPT thread on the line side, in brass or stainless, with a face seal on the metric end. The valve body is not modified.
A pressure reducing valve and a regulator hold a set downstream pressure (the first word is used for water, the second for air and gas); a relief valve opens to vent when pressure exceeds a limit; a check valve stops back-flow. They are different valves, and only their connections are covered here.
EKINSUN LTD is a custom parts manufacturer that machines valve inlet and outlet adapters, reducers, extensions, street elbows and gauge branches for ball, needle, solenoid, reducing, regulator and relief valves 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 two thread operations, length, any branch, and quantity. A brass G1/2 × 1/2 NPT adapter is a short lathe job; a 316L extension with a gauge branch is a milled and drilled part and priced as one. The quote states which.
Yes, with an adapter at each port: G1/2 male into the valve, sealing on a washer at its shoulder against the flat port face, and 1/2 NPT male into the pipe, sealing on the taper with tape. The valve body is not re-threaded; the two adapters are machined from hex bar, from 1 piece, with a quote within 12 hours.
Send the valve port and the line
Valve type and port (thread or DN), line end (thread, tube OD or hose ID), path (straight, 90°, length), material, medium, quantity. A photo of the valve port with a caliper works. 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.