Flanges Supplier
in Qatar

A raised face (RF) flange has a flat circular face raised 1.6mm (Class 150/300) or 6.4mm (Class 600+) above the pipe flange face. A spiral wound or sheet gasket sits between the two raised faces and is compressed when bolts are tightened. RF is suitable for Class 150–900 in most standard Qatar service.

A ring type joint (RTJ) flange has a precision-machined groove in the flange face. A solid metal ring gasket (oval or octagonal) seats into this groove and creates a metal-to-metal seal. RTJ is used for Class 900 and above and all API 6A wellhead flanges — mandatory for high-pressure Qatar offshore, North Field, and sour gas service where absolute sealing integrity is required.

A spectacle blind (figure-8 blind) combines a solid blind disc and an open ring spacer on a single component — like a figure 8. Installed between two flanges, it is rotated 180° to select blind position (blocking flow — positive isolation) or open position (allowing flow).

Spectacle blinds are specified to ASME B16.48 and are mandatory on many QatarEnergy piping specifications for positive process isolation during turnarounds, maintenance, and equipment isolation at Ras Laffan and offshore Qatar facilities — providing visible, auditable, lockable isolation safer than relying on a valve alone.

Spiral wound gaskets are used with raised-face (RF) flanges in Class 150 through 2500. They are the most common gasket type in Qatar refinery and process piping — good sealing performance, reasonable cost, and reusable if undamaged. They require correct bolt load to achieve proper compression.

RTJ gaskets are used only with RTJ-faced flanges and are preferred for Class 900 and above, high-temperature steam, sour gas service, and wherever a highly reliable metal-to-metal seal is required. RTJ gaskets are not reusable — a new ring must be used each time the joint is opened. For critical Qatar oil & gas connections, specify RTJ at Class 600 and above — the cost difference is small compared to the risk of a process leak.

Yes. Valiol Trading supplies flanges pre-qualified and documented for QatarEnergy, its Ras Laffan subsidiaries, and Tier-1 EPC contractors operating in Qatar. We maintain relationships with flange manufacturers who carry QatarEnergy approvals and can provide full compliance documentation. For QatarEnergy EPC projects, we also support Approved Vendor List (AVL) registration and pre-qualification submissions. Contact our Qatar engineering team with your project's material specification number for specific compliance confirmation.

Yes. We supply ASME B16.36 orifice flanges in all pressure classes and materials as matched pairs — including jack screws, ½″ NPT tapping plugs, and orifice plate holders. We can also supply the companion orifice plate (to AGA-3 / ISO 5167), differential pressure (DP) transmitters, impulse tubing, and manifold valve sets as a complete Qatar flow measurement package. Contact us with your pipe size, pressure class, and material specification for a complete package quotation including MTC 3.1 documentation.

For duplex (F51) and super duplex (F53) flanges in standard Qatar service, use ASTM A193 B8M Class 2 / A194 8M (SS 316 stud bolts and nuts) — this ensures galvanic compatibility and avoids accelerated corrosion at the bolt/flange interface. For Qatar sour gas service (H₂S environments per NACE MR0175), use ASTM A193 B7M / A194 2HM (NACE-compliant CS bolts with HRC ≤22 hardness control) or ASTM A193 B8M Class 2 stainless steel bolts — both comply with NACE MR0175 requirements for Qatar sour service applications on North Field and offshore Qatar projects. Our Qatar engineering team can confirm the correct bolting specification for your piping class.