Flared Fittings

If required, see SAE Standard J514 for a complete list of dimensions. NPT Tapered Pipe Threads meet the requirements of ASME/ANSIB.I.20.1.

All 37 Flared tube fittings 3 piece tube assembly, can be used with metric tube by using a metric 37 sleeve, instead of an inch sleeve. Each dimension table shows which metric sleeve should be used for each size.

Assembly Instructions

  1. Cut the tube to the proper length.
  2. Slide the nut and sleeve onto the tube. (See Fig.1).
  3. With a special flaring tool, form the flare to 37 dimension according to SAE J533. (see page 3).
  4. Screw the nut onto the body until finger tight.
  5. From this position, tighten the nut with a wrench 1/4″ turn in order to make a leakproof metal-to-metal connection.

Tubing Data For 37 Flare Three-piece Tube Assembly

In order to ensure maximum fitting reliability and performance,please take great care when selecting the tube for each application. Tubing should be a fully annealed, seamless and drawn, suitable for bending and flaring, according to standard ASTM-269, AISI 316 or 304.

Quality

Lengths of finished tubing should be reasonably straight and have smooth ends, free from burrs. Tubing should be free from scale and defects, and it should have a workman like finish. Surface imperfections such as handling marks, die marks, or shallow pits will not be considered injurious defects provided the imperfections are within the tolerances specified for diameter and wall thickness. The removal of such imperfections is not required. (Quality SAE J524).

Tube Handling

Scratches on the tube might cause leaks. It is, therefore, important to handle the tube carefully to reduce the risk of leaks.

  • Tubes must not be dragged on the floor.
  • Tubes must not be dragged out of a tubing rack, especially in cases of large OD tubes.

Tube Cutting

Two different methods can be used to cut tubes:

  1. Tube cutter
  2. Hacksaw

Tube Cutter

To attain a leakfree connection, the tubing must be cut squarely. A good quality tube cutter with the appropriate blade for the tubing material is recommended. Do not try to reduce the time of cutting by taking deep cuts with each turn of the cutter. The end of the tube must be deburred to avoid damage to the fitting and to ensure that the tube reaches the bottom of the fitting.

Hacksaw Cutting

In order to cut the tube with a hacksaw and to attain square ends, the tube must be cut with guide blocks. This method of cutting requires deburring of the tube ends.

Warning

Do not hold the tube in a vise in the place where it will be inserted into the fitting. The vise will leave a mark on the tube that may cause leaks and might cause ovality.