8300 Series Fittings, “O”-Rings & Sil-Braze Rings

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How the TECH-O-SEAL System Works

8300 Series Fittings, O-Rings & Sil-Braze Rings 1Two flat faced components–a threadpiece and a tailpiece–are joined by a union nut. The threadpiece is manufactured with a recessed groove that accommodates an elastic O-Ring–the secret behind this highly effective system. An initial leak proof seal is made by hand tightening the nut. Subsequent pressures in the line, by forcing the O-Ring to the outer edge of the groove, actually further strengthens the seal.



A Fitting For Every need

From 1/4″ to 2″ in diameter

8300 Series Fittings, O-Rings & Sil-Braze Rings 2

Ordering Information

Unions, Connectors, Elbows, Tees & Crosses

8300-series-1 The part numbers for all fittings may have one, two, three or four dash numbers to indicate size. Where only one dash number is given, the assembly has the same size at all ends. All dash numbers are expressed in sixteenths of an inch, as shown in the table below.

For example:

Threaded Parts

Part numbers for fittings with threaded ends always have two or three dash numbers. For example:

8300-series-2 8300-series-3


To order a reducer, two, three or four dash numbers must be given to indicate the different end sizes.


The most frequently used fittings are shown in the table. Any other fittings can be ordered by using the proper dash numbers.

Size Dash No.
1/8 -2
1/4 -4
3/8 -6
1/2 -8
5/8 -10
3/4 -12
1″ -16
1-1/4 -20
1-1/2 -24
2″ -32


To order any 8300 assembly, use the appropriate part number and the desired material designator. Standards are:

-S —- Steel
-SS —- Stainless Steel
-BRZ —- Bronze
-NICU —- Nickel Copper (Monel)
-CUNI —- Copper Nickel

Fittings are supplied with BUNA-N O-ring(s) unless otherwise specified. Order sil-braze rings (8329) separately if desired.