Port Indentification

SAE O-Ring Boss

• The male connection is a straight UNF thread with an O-Ring
• The female port has a straight thread along with a chamfer where the O-Ring seats
• Straight Thread O-Ring Boss
• Highly reliable and re-useable thread type
• While some thread types require the threads of the male and female end to crush together to form a seal, the O-Ring on this thread type crushes against the machined chamfer on the female port to form a seal.

Pipe

• National pipe tapered threads have been widely used for over 100 years. NPT is the U.S. standard for tapered threads used on pipes and fittings.
• The nominal pipe size can be identified by measuring the thread diameter and subtracting 1/4”
• They are used to effectively seal connections for fluid and gas transfer.

Metric

• Metric Port fittings utilize an o-ring/ seal washer to seal against the female port.
• Din can be utilized as a metric port fitting with the addition on an o-ring/ seal washer.
• Din has a 24 degree chamfered seat on the inside of the male fitting
• Metric threads are called out using the distance between two threads as the Thread Pitch.
• One of the most popular Metric fitting styles
• DIN fittings employ an identification system used by most manufacturers, this system combines the tube O.D. size and the tube Series
• DIN designations:
• LL = Extra Light Duty
• L = Light Duty
• S = Heavy Duty

British Standard Pipe (BSP)

• One of the most common fitting styles used worldwide.
• Available in two variations, British Standard Parallel Threads (BSPP) and British Standard Pipe Taper (BSPT)
• British Standard Parallel Threads (BSPP)
• Similar in appearance to American National Pipe Taper (NPT) adapters, they are not interchangeable due to subtle differences in size and thread form
• Seal on the 60 degree inverted flare seat of the male / tapered nose of the female, the threads are different pitches in most sizes.
• British Standard Pipe Taper (BSPT)
• More similar in appearance to American National Pipe Taper (NPT) adapters, they are not interchangeable due to subtle differences in size and thread form
• Same taper sealing style as NPT but utilizes a different thread pitch.

4 Bolt Flange (code 61, code 62, and caterpillar)

• Adapts to BSPP, SAE Straight thread and NPTF, as well as tube and pipe weld connections
• Commonly found in most industrial hydraulic fluid systems, the Four-Bolt Flange works well connecting 1/2″ to 3″ hose and tube. The seal forms between the O-ring on the male half and the smooth face of the female port. Clamps commonly held by four bolts that screw into the equipment.

note: code 61 and code 62 bolts look similar however code 62 will be thicker due to handling higher pressure.

*please refer to flange picture when looking at the letters

*Caterpillar Flanges, which are the same flange O.D. as Code 62, have a thicker flange head