KGS approval on a Korea-bound skid: which items are actually certified

There is a skid in fabrication for a Korean site, and somewhere in the client's correspondence sits the phrase "KGS approval required." Nobody in your office can say whether that covers the whole package, the vessel on it, or only two valves a sub-supplier bought in. Ask the client and the answer is that the code requires it, which is true and gets you nowhere.

Take this in the wrong order and what you lose is not the approval. It is the records. Most of what a Korean inspection asks to see has to be created while the metal is being made — filler metal certificates, welder qualification records, radiography nobody asked your fabricator to shoot. Once the job is closed and those welders are on another contract, none of it can be reconstructed. The package ships with a clean FAT report and stops at the site.

The fluid decides, not the equipment name

The High-Pressure Gas Safety Control Act draws its line at the fluid and its pressure. A compressed gas counts as high-pressure gas from 1 MPa (10 bar) gauge. A liquefied gas counts from 0.2 MPa. Compressed acetylene sits on a lower line of its own, and the Enforcement Decree carries a list of exclusions besides. The scope question is answered against the edition in force and your actual service, not against what applied on a project three years ago.

That threshold does something people find counterintuitive: identical hardware changes status with the service it carries. A nitrogen header that never works above 9 bar is outside the regime. The same spool run at 12 bar is inside it. The Act reads the pressure the line actually reaches in normal operation, and the pressure it would reach at 35 °C — not the design pressure on the datasheet. Design pressure is not idle here, but it is the trigger the occupational-safety route uses, and reading one regime with the other's number is how a package clears one and is caught by the other.

So the document to settle before anything is ordered is not the equipment list. It is the service list: fluid, operating and design pressure, and design temperature for every line and every vessel on the package.

A skid is not one regulatory object

Under the Act, a defined set of items counts as specified equipment and carries its own manufacturing and inspection route. The enforcement rule names them: storage tanks and tanks fixed to vehicles, pressure vessels, vaporizers, safety valves, emergency shut-off devices, flame arresters, valves for toxic gas piping, the components that make up refrigeration equipment, cylinder cabinets, and more. The list gets amended — EUV lithography equipment was moved onto it recently, which is a fair sign of how the list is maintained: against what is actually arriving at Korean sites. Check the edition in force for your own item, not a list from an earlier project.

Piping is not on that list. Pipe spools, supports and the structural frame are judged as part of the facility, on site, when the plant is inspected. The relief valve bolted to that piping is on the list and travels a different road entirely. That is the real answer to "where KGS approval applies," and why a single line in a quotation cannot carry it. It is also why a vendor document list sometimes asks for a fabrication-code certificate under a name no body issues: the request is shorthand for the record set behind the code, and that record set is what answers it.

The registration that has to exist before the shipment does

A manufacturer producing containers or specified equipment abroad for export to Korea registers with the Ministry of Trade, Industry and Energy. KGS runs it: prior consultation, a technical review of design and quality documentation, an on-site factory audit, then registration and a certificate renewed on a cycle. A first foreign manufacturer registration is not a matter of weeks; treat it as a lead-time item and ask KGS for the current figure. Only product from a registered maker clears import inspection — the inspection that has to pass before the item is sold or used in Korea.

Hold that against your delivery date. If the relief valve on your skid comes from a maker who is not registered, the remedy is not paperwork — it is a different valve, or a wait longer than your contract allows. The question belongs in the RFQ you send your sub-suppliers, not in the FAT punch list. Registration sits with the maker, not with you as the packager and not with the site. So what belongs on file before the purchase order goes out is the registration certificate number and its expiry, taken from the maker. Import inspection then has to sit inside the inbound schedule rather than be assumed clear.

The records that can only be made while the metal is being made

On the facility side, the plant owner applies for intermediate inspection during construction and completion inspection before the facility may be used. KGS carries both out. What gets asked for is a document set your fabricator either has or does not: contractor licence, drawings and line list, hydrostatic test records, NDE reports, material test reports for the pipe and for the welding consumables, welder qualification records, welding equipment data and the welding procedure.

The consumable certificates are the ones that go missing. Filler metal comes out of shop stock and nobody treats it as a traceable item until an inspector asks which heat went into which joint. By then the drum is empty.

The extent of NDE is set by code rather than agreed on site. For in-plant piping under the general-manufacture facility code, the designated points come out at one per 500 m of run or better, with the designated lengths totalling at least a tenth of the piping under inspection. The edition in force when the plant is built applies, so confirm the current figure before you price the radiography, not after.

Buried runs carry their own sequencing trap: a joint that has been covered cannot be presented. The inspecting office has to sit in the construction schedule ahead of backfill, and that lands on your dates: nothing goes in the ground until someone is booked to look at it. The other thing settled at site rather than in your shop is whether your flanges mate to what is already standing there.

The second authority most RFQs never mention

Pressure equipment can also be caught by the Occupational Safety and Health Act, which runs its own safety certification through KOSHA on a different trigger: design pressure above 0.2 MPa gauge, for vessels in chemical process service and for vessels handling air or nitrogen. There are exclusions — bores of 150 mm and under, vessels handling only water below 60 °C, piping components, hydraulic and pneumatic cylinders. The trigger here really is design pressure, which is why the two lists on one skid rarely match.

There is relief worth using here. Where a foreign certification body that KOSHA recognises under a memorandum of understanding has already certified the unit, part of the domestic testing can be waived under the enforcement rule. Part of it. Budget for the remainder and for the file that proves equivalence. Certification also does not end the obligation: the periodic in-service inspection that follows sits with the operator. Put that in the handover documents — the assumption that a certificate covers the life of a vessel is common.

The clock your dates actually hang from

Your client's own permitting decides when the package can be set and commissioned. Which route the site is on — a manufacturing permit, a storage installation permit, a use filing — follows from capacity and from the gas. A use filing for specified high-pressure gases is triggered at 500 kg of liquefied storage capacity or 50 m³ of compressed, and for named gases such as liquefied ammonia and chlorine it is triggered regardless of quantity. LPG runs under a separate act with its own numbers. Small does not mean exempt.

The inspection visit itself is rarely what moves your date; the file is. Processing times are published per application type and they change, so take the current figure for the filing your site is actually making. The two dates worth writing into the contract are when the registered-maker evidence for the certified items is due and when the fabrication record set is due — both ahead of shipment, not travelling with it. Assembling that file on the Korean side while your shop is still open is what delivery execution is for.

Where this gets read wrong most often

The common failure is not misreading the code. It is treating "KGS approval" as one certificate for one package and putting one line in the quotation against it. Two things follow. Either the bid prices an approval that does not exist for pipe spools, and the technical evaluation notices. Or — far more often — the assumption runs the other way: the end user handles approvals in Korea, so nothing unusual is needed in the shop. The package ships with no consumable certificates, no welder records, no radiography beyond the shop's own practice. Recovery means re-shooting film on installed pipe or swapping a component for one from a registered maker. Both are measured in months while the plant waits.

The second version is quieter and arrives late. Pressures move during detail engineering. A relief valve set point is raised to cover a revised case and the header behind it is uprated to match; a line is re-rated after a hydraulic check. A run written into the scope as ordinary piping now runs above 1 MPa in normal operation, months after the material was bought against a lower specification. Nobody re-runs the scope question, because the scope question was answered during the proposal and filed. Make it a standing check instead: every time an operating or design pressure moves on a Korea-bound package, both classifications get read again — the gas-act question against the pressure the line will actually see, the occupational-safety question against the design pressure — rather than assumed to hold from the proposal.

If you send the line list and the P&ID with services and pressures marked, we will come back with which items sit on the certified route and what your fabricator has to keep — start here.