STANDARD INSERTS

Popular couplings British Standard Pipe (BSP) threads, also known as Whitworth threads. The BSPP (parallel) male will mate with a BSPP (parallel) female or a female port. The BSPP male has straight threads and a 30° seat. The BSPP female has straight threads and a 30° seat. The female swivel BSPP has a tapered nose which seals on the cone seat of the male. The BSPP (parallel) connector is similar to, but not interchangeable with, the NPSM connector. The thread pitch is different in most sizes, and the thread angle is 55° instead of the 60° angle found on NPSM threads.

The BSPT (tapered) male mates with a BSPT (tapered) female, or a BSPP (parallel) female. The BSPT male has tapered threads. The seal between a BSPT male and a BSPT female or a BSPP female port is achieved through thread deformation. The use of a sealant is recommended. BSPT connectors are similar to NPT connectors, but they are not interchangeable. In most cases, the thread pitch is different, and the thread angle is 55° instead of the 60° angle used for NPT connectors.

This is a dryseal thread, the National Pipe Taper Fuel (NPTF) thread. It is used for both male and female ends. This connection is still widely used in fluid power systems, even through it is not recommended by the National Fluid Power Association (NFPA) for hydraulic applications. The NPTF male will mate with the NPTF, NPSF or NPSM females. The NPTF male has tapered threads and a 30° inverted seat. The NPTF female has tapered threads and no seat. The seal is achieved through thread deformation. The NPSM female has straight threads and a 30° inverted seat. The seal is achieved on the 30° seat. The NPTF connector is similar to, but not interchangeable with, the BSPT connector. In most sizes, the thread pitch is different. The thread angle is 60° instead of the 55° angle used for BSPT threads.

The NPSM female has straight threads and a 30° inverted seat. NPSM threads are used on the female swivel nuts of pipe swivel adapters. The seal is not achieved through thread contact, but through the tapered seat at the end of the connector. This type of connection is sometimes used in fluid power systems.

The DIN 24° cone male will mate with any of the three female types listed: female 24° cone with O-Ring, female metric tube fitting, or female universal 24°/60° cone. The male has a 24° seat, straight metric threads, and a recessed counterbore which matches the tube O.D. used with it. The mating female may be a 24° cone with O-Ring (DKO type), a metric tube fitting, or a universal 24° or 60° cone. DIN couplings are available in light and heavy series. Proper identification is made by measuring both the thread size and the tube O.D. The heavy series has a smaller tube O.D. than the light series, but a thicker wall section.

The DIN 60° cone male will mate only with the female universal 24° or 60° cone. The male has a 60° seat and straight metric threads. The female has a 24°/60° universal seat and straight metric threads. The seal is achieved through contact between the male cone and the female swivel. The threads maintain the connection mechanically.

A metric standpipe assembly consists of three components assembled on a male fitting: a Standpipe, a Bite Sleeve, and a Metric Nut. The nut is placed over the standpipe, followed by the Bite Sleeve. For DIN light series assemblies, a DIN light Metric Nut is used. For DIN heavy series assemblies, a DIN heavy Metric Nut is used. The Bite Sleeve and standpipe are selected based on the tube outer diameter (OD).

The Society of Automotive Engineers (SAE) specifies that a 37° flare or seat should be used for high-pressure hydraulic tubing. These connections are commonly known as JIC fittings. The JIC 37° flare male will mate only with a JIC female. The JIC male has straight threads and a 37° flare seat. The JIC female has straight threads and a 37° cone seat. The seal is achieved on the 37° flare seat by establishing a line contact between the male flare and the female cone seat. The threads maintain the connection mechanically.

The seal is achieved when the O-Ring in the male contacts the flat face of the female. These couplings are intended for hydraulic systems where elastomeric seals can be used to prevent leakage and where leak control is critical. This connection provides excellent leakage control. The male connector has a straight thread and a machined flat face. The female connector has a straight thread and a machined flat face. The seal is achieved by compressing the O-Ring against the flat face of the female, similar to a split flange fitting. The threads maintain the connection mechanically.

Japanese equipment uses JIS (Japanese Industrial Standard) couplings with a 30° seat and British Standard Pipe Parallel (BSPP) threads. The Japanese 30° flare male coupling will mate only with a Japanese 30° flare female. The male and female connectors have straight threads and a 30° seat. The seal is achieved on the 30° seat. The threads on the Japanese 30° flare connector conform to JIS B 0202, which is the same standard used for BSPP threads. Both British and Japanese connectors have a 30° seat, but they are not interchangeable because the British connector has an inverted seat.