Flow Iron & Wellhead

Match the figure, the size and the service

API 6A, API 16C and NACE MR0175

Size range

Every size above is a part number you can quote from. Open any listing for its full table.

Delivery

Flow Iron & Wellhead across the Gulf

Questions we get asked

About this range

01What do hammer union figure numbers mean?

The figure number identifies the union design and, roughly, its cold working pressure: Figure 100 is 1,000 psi, Figures 200 and 206 are 2,000 psi, Figure 602 is 6,000 psi, Figure 1002 is 10,000 psi, Figure 1502 is 15,000 psi and Figure 2002 is 20,000 psi. Each figure has its own nut thread and seal, so the figure must match on both halves of the joint. Ratings can be lower in the largest sizes of a figure, so check the size table rather than assuming the figure number.

02Can hammer unions of different figures be connected?

No. Never join halves of different figures, even when they appear to fit. Some combinations of different figures in the same nominal size can be screwed together without sealing or holding correctly, and have separated under pressure. Industry safety alerts on mismatched hammer unions stress the same rule: check the figure number and size stamped on both halves before make-up, and keep sour and standard service components apart.

03Are FMC Weco, SPM and Anson unions interchangeable?

Weco is TechnipFMC's trade name, and other makers build their figure-number unions to mate with it by figure and size. Many operators still require one maker per line or per connection, and a mixed connection should only be made where both makers state the parts are interchangeable. Tell us your operator's policy at quotation and we supply to it.

04What is the difference between standard and sour service flow iron?

Sour service parts are made for fluids containing hydrogen sulphide. Their materials meet NACE MR0175 / ISO 15156, which limits hardness — 22 HRC for carbon and low-alloy steels — so they resist sulphide stress cracking, a sudden brittle failure that standard material can suffer in H2S. Sour parts are marked as such; on a sour line every component must be sour-rated.

05What is the difference between API 6B and 6BX flanges?

API 6B flanges cover 2,000, 3,000 and 5,000 psi, take R or RX ring gaskets and are made up with a small gap between the faces. API 6BX flanges cover 10,000, 15,000 and 20,000 psi, and 5,000 psi in bores of 13-5/8″ and larger; they take pressure-energised BX rings and make up face to face. The two families do not bolt together, and an API flange is not interchangeable with an ASME B16.5 flange of similar size.

06Which ring joint gasket does a flange need?

The ring number is set by the flange's groove. R (oval or octagonal) and RX rings share groove numbers — an RX-24 fits an R-24 groove and is pressure-energised — while BX rings fit API 6BX flanges only. The ring must be softer than the groove: soft iron or low-carbon steel for standard service, 304 or 316 stainless, or Inconel 625 for sour and corrosive service. Ring gaskets are single-use; fit a new one every time the joint is broken.

07What documentation comes with flow iron and wellhead equipment?

The manufacturer's certification for the item, listed on each product page — typically the material certificate, the hydrostatic test record and a certificate of conformity, with hardness records for sour-service parts. If your operator needs more, such as a particular PSL, third-party witnessed testing or a specific certificate format, state it on the RFQ so it is confirmed before we quote.

08Which flow iron and wellhead brands do you supply?

Indus supplies TechnipFMC (FMC Weco), Cameron (SLB), SPM, Anson and Stream-Flo, and also Halliburton, NOV and Forum parts and its own flow iron, manifolds and wellhead equipment.