Sigma Polymers Engineering co. is an ISO 9001:2008 approved company established in the year 2008 with factory equipped with well-designed amenities to manufacture plastic lined systems/corrosion resistant piping systems in Ankleshwar, Gujarat. Since the beginning, we use DuPont™ Teflon®  make raw material for processing of fluoropolymer lined pipes and fittings, Lined valves and other accessories integral to the cchemical and pharmaceutical processing industries.

Design and Test Standards

All Sigma products are manufactured and tested to the international standard, with fundamental design qualification having been undertaken via the approval process required to comply with the Pressure Equipment Directive 97/23/EC.

  • Qualification Testing : EDSPIP 53.01C and ASTM F423 / ASTM F1545.
  • Design: ASME B16.5 Class 150 (except instrument tees, since these are not covered by any standard). Instrument tee is our in-house design, Approved under Pressure Equipment Directive, and in line with Relevant ASME standards.
  • Rating: Full vacuum to Class 150 at 200 C for sizes up to and including 300NB.
  • Terminations: Fixed flanges fitted off centre.
  • Dimensions: Fitting centerline to face and face to face dimensions are in Accordance with those laid down in ASME B16.5 where ever relevant.

Product Traceability

All Sigma manufactured Lined Pipes, Fittings and Valves are backwards traceable from the finished component to the manufacturing tests, processes and lining materials. Each spool has one flange stamped with the reference of the liner batch used in its construction. This provides traceability back to the liner manufactured, the tests undertaken and the materials certification of the polymer. FEP / PFA moulded items likewise are stamped with a mould reference which again provides traceability back to the manufacturing and test activities and the material certification of the polymers used.

Our Common Product Standards

All PTFE lined pipe spools are manufactured using in-house produced PTFE paste extruded liner, whilst in FEP/PFA lined fittings we use the virgin material.

All products are painted with a corrosion resistant two coat epoxy primer from outside.

All lined piping systems are provided with vent holes drilled through the steel body. They serve to inspect after production as well as indicate leaks while working. We recommend keeping vent holes always open. Closed vent holes may cause collapsing of liners due to the permeated gas pressure between lining and housing.

Special Requirements

As part of the supply Sigma can provide alternative special paint finishes, stainless steel spools & fittings, BS or DIN flanges, the use of static dissipating polymers, special low temperature service requirements, non-standard face to face dimensions, rotating flanges and the creation of special components for the reduction of flanges or to assist in tight access areas.

Product Identification and Packaging

All sigma marked products are traceable in its cross-reference to project activity, colour coding is used for identifying specific isometric drawing content. Pipes are packed well with the protective wooden waterproof end board with nuts and bolts to the flange ends. For valves and fittings, plastic moulded caps are fitted at the end.

Product Certification

Standard product certification comprises a certificate of compliance and test to EN10204 type 2.2, confirming that the products supplied to meet the relevant specifications, that fluoropolymers meet the requirements of the FDA regulation reference 21 CFR 177.1550 and details of the product tests undergone.

Project documentation – to customer specification. The following documentation can be supplied as evidence of quality control: Quality Plan, Product Drawings, Weld Procedures, Welder Qualifications, NDT Procedures, NDT Operator Qualification, Material Certification (2.2 or 3.1) and Sigma Certificate of Conformance.


  • All virgin TEFLON PTFE/FEP/PFA/PVDF/HDPE/PP7 lined products are subject to an electrostatic spark test at 15kv. All pipe spools and certain fittings are also subject to Hydrotest at 20 kg/cm2 for three minutes, followed by a relaxation dwell to atmospheric pressure and a repeat.
  • All spools and fittings lined in static dissipating PTFE/FEP/PFA are subject to Hydrotest at 20 kg/cm2 for three minutes, followed by a relaxation dwell to atmospheric pressure and a repeat.
  • All spools and fittings are visually examined, particularly the flare faces, to ensure that there are no defects that would prevent the item sealing against adjacent items.
  • The mechanical properties and the specific gravity of representative samples of PTFE liner, selected from each sinter batch, are tested.