Style S – 2.50″ – 1500 PSI Rated – Duplex Coupling and Hardware


SKU: S0250-C-BTD-D-D Category:


Style S couplings incorporate the more noble, duplex-alloy construction, which although initially more expensive, offers the superior corrosion resistance and corresponding better longevity for highly corrosive environments compared to the Style B coupling which is constructed from 316 alloy. Consult Piedmont application engineering for guidance on the selection of metal alloy for your application.



Pressure Rating: 1500 psi (103 bar) with schedule 40s pipe (special alloys) with cut groove only – all sizes.



Duplex or Superduplex stainless steel type CE8MN (UNS # J93345) conform to ASTM A995, Grade 2A requirements. Piedmont also offers this coupling in superduplex type CE3MN (UNS # J93404) conform to ASTM A995, Grade 5A requirements for higher resistance to corrosion. Other alloys are also available.


EPDM rubber, suitable for hot and cold water services. Two shapes of gaskets are available: C-shaped or Flush-fit. NSF/ANSI 61 approved or equivalent for drinking water system components. Not suitable for petroleum service. *EPDM peroxide cured gaskets available upon request (for special applications such us chloramines, etc…)


Round / hexagonal head, oval neck, 316 stainless steel bolts dimensional specifications conforming to ASME B18.5 – 2012. For couplings sizes from ¾’’ to 3’’, use heavy hex type 651 silicon bronze nuts, for couplings of 4’’ and up use 316 stainless steel nuts. Washers are heavy pattern 316 stainless steel.

* For the use of Style S couplings on cyclic axial displacement systems, please consult with Piedmont for design and installation guidance.

Note: Working pressure ratings based upon generally accepted pressure piping design standards and testing in accordance with ASME Section VIII Division 1 pressure vessel test method.

MPN: S0250-C-BTD-D-D

Piedmont Style S Grooved Coupling Technical Information

Piedmont Style S Grooved Coupling Product Sheet

Additional information

Weight 1.5 lbs
Dimensions 2 × 2 × 4 in

Duplex, EPDM



Pressure Rating

1500 PSI

Max Pressure (Bar)

103.4 bar

Coupling Style

Style S Duplex