How to Convert Your Food Van to LPG (UK Guide 2026): Equipment, Costs & CP44

Last updated: May 2026

Last updated: May 2026

To convert a food van to LPG in the UK, you need a propane (G31) cylinder, a 37 mbar regulator, BS 3212-rated armoured flexible hose, a 30 mb under-pressure shut-off (OPSO), low-level drop-out ventilation, an accessible emergency shut-off valve, and a CP44-qualified LPG vehicle engineer to design, install and certify the system. Without a current CP44 certificate, you cannot legally trade at any UK licensed market, festival or street food event.

That is the short answer for the trader who came here in a panic the night before a pitch. The rest of this guide is the long answer — the parts the supplier won’t always tell you, the costs you can plan around, and the questions every CP44 engineer is going to ask before they pick up the phone. We’ve worked with mobile traders, builders and event organisers across the UK, and almost every “my fryer keeps cutting out” call traces back to a corner cut on the conversion. So this is the kit list, the cost range, the engineer-finding process, and the inspection checklist all in one place — written for traders who actually have to live with the install.

What converting a food van to LPG actually involves

An LPG conversion replaces a vehicle’s general gas plumbing with a fully certified propane installation rated for commercial mobile catering. A qualified engineer will fit a propane cylinder (or twin cylinders with a changeover valve), a 37 mbar regulator with built-in OPSO and UPSO safety devices, BS 3212 flexible armoured hose with crimped ferrules, a low-level ventilation drop-out panel, an emergency shut-off, and rigid pipework or appliance flexes to each gas appliance. They then pressure-test the whole system to confirm there are zero leaks, document the install, and issue your CP44 certificate.

For a typical 14ft–18ft trailer with three to five appliances, a competent engineer can complete the work in a single day. New-build trailers being kitted out from bare aluminium take longer — usually two days — because the engineer is also routing the pipework cleanly behind cladding rather than retrofitting around an existing kitchen. Either way, propane is the only fuel you should be running. Butane stops vaporising reliably below about 2°C, which kills appliances on any cool morning — meaning roughly half the UK trading year. Every commercial mobile-catering appliance sold in the UK is rated for propane at 37 mbar, full stop.

The equipment you need for an LPG installation

Below is the kit list every CP44-compliant install in the UK should have. Skip any one of these and you’ll either fail certification or trip up the first time an event organiser asks for sight of your gas paperwork.

• Propane (G31) cylinder or cylinders: Always orange, always propane. Common sizes are 13kg (compact) and 19kg (standard for higher-load trailers). Twin cylinders connected through an automatic changeover valve let you trade through a swap without service interruption — a near-essential upgrade for full-day events. MobCater stocks the automatic LPG changeover valve fitted with OPSO as our recommended dual-cylinder solution.
• 37 mbar propane regulator with OPSO/UPSO: The pressure regulator drops cylinder pressure to the 37 mbar your appliances expect. Over Pressure Shut Off (OPSO) and Under Pressure Shut Off (UPSO) are integrated safety devices that close the supply if pressure drifts outside safe limits. Don’t accept a regulator without both.
• BS 3212-rated flexible armoured hose: Steel-braided propane hose with crimped end fittings. Never use rubber garden-style hose, regardless of how the cylinder connects to the regulator. Hose is a wear item — most insurers expect replacement every five years.
• Drop-out ventilation panel: LPG is heavier than air and sinks to the floor. Catering vans require a low-level vent (typically along the lower serving hatch edge or a dedicated floor-level vent) so any leak dissipates safely rather than accumulating under your appliances.
• Emergency isolation valve: An accessible shut-off valve allowing you — or a responder — to immediately cut the supply. Must be clearly labelled and reachable from outside the cooking area.
• Rigid copper pipework or appliance flex: Internal pipework is either fixed copper (preferred for static appliances like a coffee machine or fryer) or short purpose-built flexes for portable appliances. Crimped joints only — no compression fittings on LPG inside a vehicle.
• CO and gas-leak alarms: Carbon monoxide and combustible gas alarms are no longer optional in any responsible install. Most event organisers ask to see them mounted before granting a pitch.

Finding a CP44-qualified gas engineer

Only an engineer holding the CP44 certificate of competence (or an equivalent LPG vehicle qualification) can legally design, install and certify a gas system in a mobile catering vehicle in the UK. A standard domestic Gas Safe registration is not enough — vehicle work is its own category, and you should never accept a domestic-only engineer signing off your trailer.

The straightforward way to find a properly qualified engineer is the Gas Safe Register search tool. Filter for engineers in your region and confirm CP44 (LPG mobile catering) appears under their listed competencies before booking. Ask three direct questions on the call: do they hold an in-date CP44? have they certified mobile catering vehicles before? and will they provide both the certificate and the supporting paperwork (regulator certificate, hose batch numbers, leak-test record) in writing?

An engineer who hesitates on any of those is the wrong engineer. The good ones answer instantly because they’re proud of the audit trail. For more on what the certificate covers and why event organisers insist on it, see MobCater’s CP44 gas safety certificate guide.

What does an LPG conversion cost in 2026?

Total spend on a properly specified LPG conversion in the UK typically lands between £470 and £1,030 (from £470 at the budget end), depending on whether you’re retrofitting an existing trailer or kitting out a bare build, and how many appliances need to be plumbed in. Here’s how the budget actually breaks down for a typical mid-size trailer:

• CP44 engineer labour and certificate: from £180 to £350 depending on region and whether they travel to you or you take the trailer to their workshop. Day rates in London and the South East sit at the top of that range.
• Propane regulator with OPSO/UPSO: from £45 to £85 depending on flow rate (you need higher flow for fryers, water heaters and salamanders).
• Automatic changeover valve (twin cylinder upgrade): from £95 to £140. Strongly recommended if you trade events longer than a single 19kg cylinder will last.
• BS 3212 armoured hose set with crimped ends: from £35 to £65 per cylinder pigtail.
• Rigid copper pipework, fittings, isolation valves: from £70 to £180 depending on appliance count and pipe runs.
• Drop-out ventilation panel and grille kit: from £25 to £55. Often retrofitted as part of the install.
• CO and combustible gas alarms: from £20 to £55 for a competent dual alarm.

Cylinders themselves aren’t usually a one-off cost — propane bottles are loaned by the supplier (Calor, Flogas) under a refill agreement. You pay a one-time cylinder deposit (commonly from £45 to £75 each) and then refill cost on top. Two 19kg propane cylinders on changeover will keep most mobile traders running through a full event day with margin to spare.

What the CP44 engineer inspects on certification

The certification visit is the bit that catches first-time traders out. The engineer is not just checking the install works — they are auditing every joint, every hose end, and every safety device against a published standard. Expect them to test and document every one of the items below:

• Cylinder restraint: Cylinders must be physically secured upright, in a vented compartment, with no risk of tipping during transit. Loose cylinders fail immediately.
• Regulator and pigtails: Date-marked, in date, correctly torqued. Regulators have a service life — typically 10 years — and the engineer will replace any that’s out of date.
• Pressure-tightness test: The engineer applies test pressure and watches a manometer for any drop over a fixed period. A leak measured in millibar means a fail.
• Appliance certification: Every connected appliance must itself be a commercially-rated LPG appliance. Domestic gas hobs and patio cookers are non-starters — they will fail and they invalidate insurance.
• Ventilation: The drop-out vent’s location and free area against trailer volume.
• Isolation and emergency shut-off: Reachable, labelled, and functioning.
• Alarms: CO alarm and combustible gas alarm in date, mounted, and audible.
• Documentation: Regulator certificate, hose batch records, leak-test record, and the CP44 certificate itself, all left with you in writing.

The CP44 certificate itself is valid for 12 months. Recertification is annual, and most engineers will run a quick service alongside the test — checking burners, replacing perished hose, and topping up alarm batteries.

Frequently asked questions: converting a food van to LPG

What does converting a food van to LPG involve?

It involves fitting a propane cylinder system, a 37 mbar regulator with OPSO and UPSO, BS 3212 armoured hose, low-level drop-out ventilation, an emergency shut-off valve, and rigid pipework to each appliance, then having the whole installation pressure-tested and certified by a CP44-qualified gas engineer. The conversion typically takes a single day for a retrofit and two days for a new-build trailer.

What equipment do I need for an LPG installation in a catering van?

You need a propane G31 cylinder (commonly 13kg or 19kg), a 37 mbar regulator with built-in OPSO and UPSO, BS 3212 flexible armoured hose with crimped ends, a low-level ventilation drop-out panel, an accessible emergency shut-off valve, rigid copper pipework with crimped joints, and CO plus combustible-gas alarms. A twin-cylinder setup with an automatic changeover valve is strongly recommended for full-day events.

What size LPG cylinder do I need for a catering van?

Most mobile caterers run 19kg propane cylinders for a typical event day, often paired on an automatic changeover so one is always on-line while the other is reserved. A 13kg cylinder is fine for a smaller setup with one or two appliances. The realistic rule of thumb: a 19kg cylinder will run a typical fryer, griddle and water heater combination for around 8–12 hours of trading, depending on how aggressively each appliance is being used.

How much does it cost to convert a food van to LPG in the UK?

Total cost for a properly specified conversion in 2026 is typically from £470 to £1,030, depending on appliance count, whether you choose a single or twin-cylinder setup, and your engineer’s regional day rate. The CP44 engineer’s labour and certificate accounts for from £180 to £350 of that, with the remainder going on the regulator, hose, pipework, alarms and ventilation kit.

Do I need a CP44 certificate to run LPG in a catering van?

Yes. The CP44 (or recognised equivalent) is the legally required certificate of competence for LPG installations in mobile catering vehicles in the UK. Event organisers, market authorities and your insurer will all expect to see a current certificate before you trade. Without it, you can be removed from a pitch on the day and your insurance is likely to be invalid in the event of a gas-related claim. See MobCater’s full CP44 guide for the regulatory detail.

Can I use butane instead of propane in my catering van?

No. Butane is unsuitable for UK mobile catering. It stops vaporising reliably at around 2°C, which means it effectively stops working on any cool morning — and that covers roughly half of the UK trading calendar. Propane (G31) vaporises reliably down to around -40°C and is the correct fuel for every commercial mobile catering application. Every UK catering appliance rated for LPG is designed for propane at 37 mbar. Using butane risks inconsistent pressure, mid-service appliance cut-outs, and potential safety issues that will fail your CP44 inspection.

How often does an LPG installation in a catering van need to be recertified?

Annually. The CP44 certificate is valid for 12 months from the date of issue. Most engineers will run a routine service alongside the recert: pressure-testing the system, replacing any perished hose, checking the regulator’s service-life date, and confirming alarms are in date. Budget from £150 to £220 for an annual recertification on a settled, well-maintained install.

What happens if I trade without a current CP44 certificate?

You can be removed from your pitch immediately. Most UK event organisers, local authority markets and licensed festivals require sight of an in-date CP44 before they hand over a trader pass. If a gas-related incident occurs while you are out of cert, your insurer will almost certainly refuse the claim, and your local trading standards team can take separate enforcement action. The cost of recertification is a fraction of a single missed event — there is no realistic upside to trading uncertified.

Related guides

If you’re at the conversion stage, you’ll also want to plan the wider off-grid setup — read MobCater’s mobile catering equipment guide for the full kit list, MobCater’s LPG generator guide for off-grid power, and MobCater’s LPG water boiler guide for the only LPG-rated commercial water boiler made in the UK.