FLAGSHIP▶ HOVERHeader & Shoulder Plugs
API 661 type hex head UNF plugs and matched gaskets for header boxes on air-cooled heat exchangers and fin-fan coolers.
3/4" – 2-1/8"12 UNF / 14 / 1612 alloysPlug + gasket sets
Instrumentation · Valves · Heat exchanger parts
Precision thatseals first time.
Since 1992, Metalok Industries has machined header plugs, instrumentation valves, manifolds and fittings that refineries, EPCs and OEMs install without a second thought.
ISO9001:2015 certifiedCEMarked productsPEDCertifiedAPI661 type header plugsEN10204 3.1 / 3.2 certificatesASMESA-182 · SA-105 · SA-350115+Export countries1992Manufacturing sinceISO9001:2015 certifiedCEMarked productsPEDCertifiedAPI661 type header plugsEN10204 3.1 / 3.2 certificatesASMESA-182 · SA-105 · SA-350115+Export countries1992Manufacturing since
●Oil & Gas●Refineries●Petrochemical●Power Plants●Fertilizers●Air-Cooled Heat Exchangers●Offshore Platforms●EPC Contractors●OEM Skid Builders●Oil & Gas●Refineries●Petrochemical●Power Plants●Fertilizers●Air-Cooled Heat Exchangers●Offshore Platforms●EPC Contractors●OEM Skid Builders
SINCE1992
IN STOCKHeader plugs, 3/4" to 2-1/8"
01 About Metalok
Built for the parts of a plant nobody wants to think about twice.
Metalok Industries is a Mumbai-based manufacturer and exporter of instrumentation fittings, valves, manifolds and heat exchanger components. For over three decades we have supplied the oil & gas, petrochemical, power and fertilizer industries with parts that are machined right, marked for traceability and shipped with the paperwork your inspector expects.
- ISO 9001:2015, CE & PED certified quality management system
- 24 product families: from needle valves to tube sheets
- Certified, skilled workforce and in-house testing facilities
1992Manufacturing since
115+Export countries
24Product families
12+Alloy families machined
02 Why buyers switch to Metalok
Six reasons engineers sign off on our parts faster.
TRACEABILITY
Heat number on every part
Each plug, fitting and valve body is marked with the Metalok name, material grade and heat number, and backed by an EN 10204 3.1 certificate.
PRECISION
CNC-machined, gauge-checked
Threads are CNC cut and gauged; sealing faces are finished to 63 RMS so the gasket seats leak-tight on the first torque.
METALLURGY
12+ alloy families
Carbon steel, 316 SS, Cr-Mo, Duplex, Monel, Inconel, Titanium, Hastelloy, CuNi and more, matched to your process media.
SPEED
Stock sizes, fast dispatch
Standard header plug sizes from 3/4" to 2-1/8" are stocked for shutdown and turnaround work. No minimum order quantity.
CUSTOM
Built to your drawing
Non-standard threads, lengths and exotic alloys made to your spec, with high-volume daily production capacity.
EXPORT
Trusted in 115+ countries
Export documentation, seaworthy packing and third-party inspection support for EPCs, refineries and OEMs worldwide.
03 Product range
From the instrument tap to the header box.
Hover any range to see it in motion. Add items to your RFQ list and send them all in one go.
FLAGSHIP▶ HOVER
VALVES▶ HOVERInstrumentation Valves
Needle, ball, check, relief and bleed valves for instrument isolation up to 6000 PSI.
NeedleBallCheckRelief
MANIFOLDS▶ HOVERManifold Valves
2, 3 and 5 valve manifolds for pressure transmitters and DP measurement.
2-valve3-valve5-valve
QUARTER-TURN▶ HOVERBall Valves
Compact two- and three-piece instrument ball valves with lockable levers.
NPT / BSPTube endsSS 316
FITTINGS▶ HOVERCompression Tube Fittings
Twin-ferrule unions, elbows, tees and connectors for leak-tight instrument tubing.
UnionElbowTeeConnector
FLANGES▶ HOVERFlanges
Weld neck, slip-on, blind and threaded flanges in SS, CS and alloy grades.
WNSOBlindThreaded
HEAT EXCHANGER▶ HOVERTube Sheets
Precision-drilled tube sheets and baffles to your hole pattern and pitch.
DrilledMachinedCustom pitch
Can't find it?
Air headers, condensate pots, thermowells, DBB monoflanges, couplings & more
Send your spec or drawing. If it's in instrumentation or heat exchanger service, we likely make it.
HEX HEADLaser-marked: grade, size, heat no.
FLAT GASKETSoft iron, SS or alloy, matched OD/ID
63 RMS FACEGasket seat finished for first-torque seal
UNF THREADCNC cut, gauge-checked, 12 TPI
04 Seal-tight by design
A header plug is only as good as its seat.
Leaks in air-cooled exchangers usually start at the plug: a rough seat, a mismatched gasket, a thread cut a fraction off. Every Metalok plug is engineered around the seal.
- Precision UNF threads
CNC-cut and gauged for a smooth, full-engagement fit. - 63 RMS gasket seating face
Finished so the gasket compresses evenly at recommended torque. - Matched plug & gasket sets
Supplied together, so there's no mixing of sizes on site.
05 Quality & traceability
How to read a Metalok plug.
Every plug carries its own paperwork, engraved into the hex. Tap a marker to see what each line tells your inspector.
06 Manufacturing capability
Turned, threaded and inspected under one roof.
CNC turning centres run high-volume production every day, with in-house testing and inspection before anything is packed.
CNC TURNINGThreads, sealing faces & hex in one setup
THREAD GAUGINGGo / no-go on every batch
TESTINGHydro & pressure testing for valves
MARKINGLaser-marked grade & heat number
07 Engineering tools
Not sure which alloy? Ask the selector.
Pick your service conditions and we'll suggest the material families engineers typically specify, each with its Metalok order code.
Alloy selector
Match the metal to the media.
Choosing the wrong grade is the most expensive mistake in plugs and fittings. This guide narrows it down in one click.
Next: size your header plug →
STEP 1 · SELECT SERVICE CONDITION
STEP 2 · RECOMMENDED MATERIAL FAMILIES
Indicative guidance only. Final selection should follow your design code and process licensor; our engineers will confirm.
08 How it works
From RFQ to your site in five steps.
01
Send your RFQ
Size, material, quantity, or just a drawing.
02
Spec review & quote
Engineering check and priced quote in one working day.
03
Machining
CNC production from certified raw material.
04
Inspection & MTC
Gauging, testing, marking, EN 10204 3.1.
05
Packed & shipped
Export packing, documents, courier, air or sea.
Catalogues & datasheets
Header & Shoulder Plugs datasheet: sizes, torque, gaskets & materials on one page.
09 Industries served
Wherever pressure, temperature and media are unforgiving.
Oil & Gas / Refineries
Header plugs, needle valves, manifolds, DBB valvesPetrochemical
Compression fittings, check valves, thermowellsPower Generation
Condensate pots, air headers, ball valvesFertilizers
Instrument valves, flanges, CuNi & SS fittingsAir-Cooled Heat Exchangers
Header & shoulder plugs, gaskets, tube plugsProcess & OEM Skids
Manifolds, quick-release couplings, tube & pipeWhat you need
Typical trader
Metalok Industries
Manufacturer-direct pricing
✕ Marked up
✓ Direct from works
Heat-number traceability
✕ Often missing
✓ On every part
EN 10204 3.1 certificates
On request
✓ Standard
Custom threads & alloys
✕ Not possible
✓ To your drawing
Minimum order
Box / carton
✓ No MOQ
10 Buyer feedback
Trusted on shutdowns, turnarounds and new builds.
★★★★★
Shutdown spares for our fin-fan coolers arrived complete, sized and marked by heat number. The plug and gasket sets were matched, so the crew had no sorting to do on site.
MP
Maintenance PlannerRefinery, Saudi Arabia
★★★★★
Clear quotations, correct MTCs and on-time dispatch. Their team answers technical questions on WhatsApp the same day, which matters when a project is moving.
PM
Procurement ManagerEPC contractor, UAE
★★★★★
We moved our 2- and 5-valve manifolds to Metalok. Finish, threads and pressure testing are consistent batch after batch.
IE
Instrument EngineerFertilizer plant, India
★★★★★
Custom thread plugs in Duplex were made exactly to our drawing. Packing and documentation were export-ready.
PH
Purchase HeadHeat exchanger OEM, Malaysia
★★★★★
No-MOQ ordering lets us keep a small stock of every plug size instead of over-buying. Re-orders are simple.
SI
Stores & Inventory LeadPetrochemical complex, Oman
★★★★★
Material marking, traceability and certificate quality were in order at final inspection. A well-run shop floor.
QI
QA/QC InspectorThird-party agency, Qatar
★★★★★
Shutdown spares for our fin-fan coolers arrived complete, sized and marked by heat number. The plug and gasket sets were matched, so the crew had no sorting to do on site.
MP
Maintenance PlannerRefinery, Saudi Arabia
★★★★★
Clear quotations, correct MTCs and on-time dispatch. Their team answers technical questions on WhatsApp the same day, which matters when a project is moving.
PM
Procurement ManagerEPC contractor, UAE
★★★★★
We moved our 2- and 5-valve manifolds to Metalok. Finish, threads and pressure testing are consistent batch after batch.
IE
Instrument EngineerFertilizer plant, India
★★★★★
Custom thread plugs in Duplex were made exactly to our drawing. Packing and documentation were export-ready.
PH
Purchase HeadHeat exchanger OEM, Malaysia
★★★★★
No-MOQ ordering lets us keep a small stock of every plug size instead of over-buying. Re-orders are simple.
SI
Stores & Inventory LeadPetrochemical complex, Oman
★★★★★
Material marking, traceability and certificate quality were in order at final inspection. A well-run shop floor.
QI
QA/QC InspectorThird-party agency, Qatar
Representative feedback for demo · to be replaced with Metalok's verified customer reviews
11 Start an enquiry
Send the spec.
Send the spec.
Get a priced quote within one working day.
Tell us the product, size, material and quantity. Attach a drawing or datasheet if you have one, and our sales engineers will come back with price, lead time and certification scope.
12 Questions
Answers before you ask.
No. Standard sizes can be ordered from a single piece, which is useful for shutdown spares. Volume pricing applies for larger quantities and annual rate contracts.
Most RFQs with a clear size, material and quantity are quoted within one working day. Custom drawings may take a little longer while our engineers review the details.
Yes. Send your drawing (PDF, DWG, STEP) with material and quantity. We machine non-standard threads, lengths and exotic alloys to your specification.
Standard header plug sizes from 3/4" to 2-1/8" and common fittings and valves in SS 316 and carbon steel are stocked for fast dispatch.
Metalok Industries is ISO 9001:2015 certified, with CE marking and PED certification for applicable products.
Yes. EN 10204 3.1 certificates are supplied with every consignment. EN 10204 3.2 and third-party inspection can be arranged at order stage.
Every part is marked with the Metalok name, material grade and heat number, which links back to the mill certificate and our inspection records.
We export to customers in 115+ countries across the Middle East, Africa, Europe and Asia, for refineries, EPC contractors, OEMs and distributors.
We quote EXW, FOB Nhava Sheva or CIF/CFR as required, by courier, air or sea freight, with export-grade packing and full documentation.
Yes. Buyer and third-party inspection (TPI) at our works is welcome with advance notice.
Start a project
Shutdown next month? Send the list today.
We'll check sizes, materials and stock and reply with a priced quote within one working day.