01 / 11FLAGSHIP
Header & Shoulder Plugs
API 661-type plugs with matched flat gaskets for air-cooled exchanger header boxes. 12 sizes, 12 alloys.
ISO 9001:2015 · CE · PED certified · Since 1992
Engineered to
Engineered to
Header & shoulder plugs, instrumentation fittings, valves and manifolds — machined in Mumbai for the plants that cannot afford a single leak.
EN 10204 3.1API 661 type plugs12+ alloys0 MOQ
ISO9001:2015 certifiedCEmarked productsPEDcertified3.1EN 10204 certificates115+export countries1992manufacturing sinceAPI 661type header plugs12+alloy familiesISO9001:2015 certifiedCEmarked productsPEDcertified3.1EN 10204 certificates115+export countries1992manufacturing sinceAPI 661type header plugs12+alloy families
Oil & GasRefineriesPetrochemicalPowerFertilizersAir-cooled heat exchangersEPC contractorsExchanger OEMsStockistsShutdown teamsOil & GasRefineriesPetrochemicalPowerFertilizersAir-cooled heat exchangersEPC contractorsExchanger OEMsStockistsShutdown teams
01 · About Metalok
We machine the smallest parts in the plant — the ones that decide whether it keeps running.
● Production batch · header plugs
Metalok Industries is a Mumbai manufacturer and exporter of instrumentation fittings, instrumentation and manifold valves, DBB valves, industrial valves, heat-exchanger parts, flanges, fasteners and raw material — trusted by oil & gas, refining, petrochemical, power and fertiliser plants.
0Manufacturing since
0Countries supplied
0Product families
0Alloy families
02 · The collectionBuilt for the header box,
Built for the header box,
the impulse line and everything between.
0111
02 / 11
Instrumentation Needle Valves
Fine-control isolation for impulse lines and analyser systems, bar-stock bodies.
03 / 11
Ball Valves
Quarter-turn instrument ball valves for quick, positive shut-off.
04 / 11
Manifold Valves
2, 3 and 5 valve manifolds for pressure and DP transmitter hook-ups.
05 / 11
Compression Tube Fittings
Twin-ferrule tube fittings that make leak-tight joints on instrument tubing.
06 / 11
Flanges
Forged flanges in carbon, alloy and stainless steels to buyer standards.
07 / 11
Tube Sheets
Drilled tube sheets and baffles for shell-and-tube and air-cooled exchangers.
08 / 11Check Valves
Instrument check valves that stop reverse flow on small-bore lines.
09 / 11Butt Weld Fittings
Elbows, tees, reducers and caps for process piping and tie-ins.
10 / 11Pipes, Plates & Raw Material
Seamless and welded pipes, coils, sheets, plates, angles, channels and bars.
11 / 11Fasteners
Stud bolts, hex bolts, nuts and washers in carbon, alloy and stainless grades.
Not in the line-up?
Send the drawing.
Special plugs, adaptors, thermowells and machined parts are made to your drawing and grade.
03 · Anatomy of a sealHow one plug
How one plug
holds a header box.
Scroll to assemble a 1-1/8" Metalok header plug — values from our own catalogue.
01The bore
Each tube in an air cooler lines up with a threaded hole in the plug sheet. That hole is where leaks begin.
02The gasket
A matched flat gasket lands on a 63 RMS seating face. Plug and gasket are supplied as one set.
03The plug
1-1/8" diameter, 12 UNF thread, 1-1/2" hex — laser-marked with grade and heat number.
04The torque
Tightened to the catalogue minimum of 395 ft-lb (≈ 536 N·m). The box is sealed.
METALOK · MISP-G-11250%
OPEN
0FT-LB APPLIED
04 · WHY BUYERS SWITCH
Six reasons the purchase file stays with Metalok.
We don't sell parts by the kilo. We sell the confidence that a header box, a transmitter line or a flange joint will hold — and the paperwork to prove it.
Matched plug + gasket sets
Every plug ships with the gasket sized to it — OD, ID and material matched. No mix-ups at the header box.
Traceable to the heat number
Metalok name, grade and heat number are laser-marked on every head.
EN 10204 3.1 as standard
Mill-certified raw material and 3.1 certificates with every consignment; 3.2 on request.
12+ alloy families
Carbon steel to Titanium, Hastelloy and Zirconium — plus Duplex and 904L on request.
Shutdown-ready dispatch
High-volume production with fast delivery from stock for turnaround schedules.
No minimum order
One urgent spare or a full exchanger set — the same engineering attention.
05 · APPLICATION FINDERPick your plant.
Pick your plant.
Get your Metalok kit.
Choose an industry and the equipment you maintain. We'll list the Metalok product families that go with it — add the whole kit to your RFQ in one tap.
1INDUSTRY
2EQUIPMENT
3YOUR KIT
General guidance only — final selection is confirmed by our engineers against your datasheet.
06 · FROM BAR TO BOX
Six checkpoints between raw bar and your site.
Precision is not a slogan on the brochure. It is a sequence of checks that happen to every part, every batch.
CNC TURNING · MUMBAI WORKS
01
Mill-certified bar
Raw material from approved mills, with original mill certificates on file.
02
CNC turning
Plugs and fittings are turned on CNC lathes for repeatable dimensions batch after batch.
03
Thread gauging
Every thread is checked with go / no-go gauges before it moves on.
04
63 RMS sealing face
Gasket seats are finished and inspected to the specified surface finish.
05
Laser marking
Metalok name, material grade and heat number on every head — full traceability.
06
3.1 MTC & export packing
EN 10204 3.1 certificates, capped threads, ISPM-15 boxes labelled by PO line.
07 · Industries we serve
01
Oil & Gas
Wellhead instrumentation, DBB isolation and manifold hook-ups that hold in harsh service.
02
Refineries
Header plugs, tube plugs and tube sheets for the exchangers that keep crude units running.
03
Petrochemical
Flanges, fittings and valves in the alloys your process chemistry demands.
04
Power
Condensers, feed-water heaters and instrument lines — built for long campaigns.
05
Fertilizers
Corrosion-resistant valves and fittings for ammonia and urea plants.
06
Air-cooled exchangers
API 661-type header and shoulder plugs for fin-fan OEMs and maintenance teams.
08 · Datasheet
The whole header plug range on one page.
- Sizes for 5/8" to 2" tube O.D.
- Threads, hex sizes and gasket stock numbers
- Minimum torque per size
- 12 material codes and 5 coating options
09 · Buyers on recordQuiet shutdowns.
DEMO REVIEWS · REPLACE WITH REAL CUSTOMER FEEDBACKQuiet shutdowns.
Happy purchase teams.
We ordered header plugs and gaskets for a fin-fan retrofit. Every plug came with the matched gasket and heat number — QC signed off on day one.
PM
Procurement ManagerEPC contractor · Abu Dhabi, UAE
Shutdown order turned around faster than our usual vendor, with 3.1 certificates in the same box.
MH
Maintenance HeadRefinery · Gujarat, India
Clear drawings, clean threads, sensible prices. Our repeat supplier for plugs in SS and Monel.
DR
DirectorACHE fabricator · Dammam, KSA
Manifolds and tube fittings arrived well packed and labelled by PO line. Made site reconciliation easy.
IE
Instrument EngineerFertilizer plant · Lagos, Nigeria
Responsive export desk on WhatsApp and correct paperwork every time.
PL
Purchase LeadStockist · Rotterdam, Netherlands
We ordered header plugs and gaskets for a fin-fan retrofit. Every plug came with the matched gasket and heat number — QC signed off on day one.
PM
Procurement ManagerEPC contractor · Abu Dhabi, UAE
Shutdown order turned around faster than our usual vendor, with 3.1 certificates in the same box.
MH
Maintenance HeadRefinery · Gujarat, India
Clear drawings, clean threads, sensible prices. Our repeat supplier for plugs in SS and Monel.
DR
DirectorACHE fabricator · Dammam, KSA
Manifolds and tube fittings arrived well packed and labelled by PO line. Made site reconciliation easy.
IE
Instrument EngineerFertilizer plant · Lagos, Nigeria
Responsive export desk on WhatsApp and correct paperwork every time.
PL
Purchase LeadStockist · Rotterdam, Netherlands
10 · ENQUIRY
Let's talk spec.
Send a size, a drawing or just a tag number. An engineer — not a call centre — answers with price, lead time and the right grade.
WhatsApp export desk+91 83692 90665
Toll-free (India)1800 2099 630
Mobile+91 98695 52950
Emailsales@metalokindustries.com
Unit No. 21, Nikisha Industrial Estate, Western Express Highway, Pandurang Wadi, Mira Road East, Mumbai, Maharashtra 401107, India
Metalok Industries has been manufacturing since 1992 and exports to customers in 115+ countries.
Metalok is an ISO 9001:2015, CE and PED certified company. Certificates are shared with your enquiry on request.
Our works are at Nikisha Industrial Estate, Mira Road East, on the Western Express Highway (Mumbai region). Buyer and third-party inspection visits are welcome with notice.
No. We supply from a single urgent spare to complete exchanger sets.
Use “+ RFQ” on any product or the plug configurator to build a list, then send it in one go on WhatsApp or email. You can also attach your own RFQ sheet by email.
Yes. Special plugs, fittings, adaptors and machined components are made to your drawing and material specification.
Stock sizes are typically dispatched within days. Tell us your required date and we will confirm a firm schedule with the quotation.
EN 10204 3.1 mill test certificates come with every consignment; 3.2 with third-party witness on request.
Domestic: ex-works Mumbai. Export: EXW, FOB Nhava Sheva or CIF as agreed.
Threads and sealing faces are capped, parts are bagged by size, and export boxes are ISPM-15 heat-treated where required, labelled by item, size, material, heat number and PO.