ASME B16.9 is standard specification for butt welding fittings that covers BW concentric eccentric reducer, elbow tee. The dimensions range is 3/4" to 24" in seamless type.

Compare with cone-shaped fitting that enlarges reduces the diameter, it is symmetrical about center line. Both of them are available in carbon steel, alloy steel, stainless steel used in pipeline system for reducing the diameter one size to larger small size.

Buttwelding Fittings are used in a piping system to change direction function of media, to branch off, reduce pipe size attach auxiliary equipment. They are availbale in multiple types as elbow, tee, cap, eccentric reducer, stub end oelt, that produced in cold hot forming based on ASTM A403 ASTM A234 specification.

ASTM A403 WP304 & 316 Stainless Steel Pipe Fittings

The specification of ASTM A403 covers common stainles steel grades WP304 & WP316 that used for pressure piping. Customers need to indicate seamless welded type while purchasing kinds grades fittings, such as eccentric reducers, buttwelding tee & cross, steel pipe bend elbow.

ASTM A234 Carbon Steel Alloy Steel Pipe Fittings

This specifiation covers ASTM A234 carbon steel alloy steel fittings of semaless welded construction by the standard of ASME B16.9. These eccentric reducer fitting is for using in pressure piping in pressure vessel fabrication for service at moderate elevated temperatures.

BW Eccentric Reducer Fitting Specifcation

ASME B16.9 Eccentric Reducer Dimensions

Notes

1) Besides the above mentioned standards, the standards of GB/T 10752 SH 408   SH 3409   HG/T 21635   HG/T 21631   SY/T 0510   DL/T 695   EN 10253 etc.are also applied.

2) For the concentric eccentric reducers with the sizes larger than that listed in the above table, they will be supplied subject to the sizes agreed by purchaser manufacturer according to manufacturer's size.