Converting Your Food Van to LPG: Equipment, Costs & Gas Safety Requirements
Converting a food van to LPG means fitting a propane G31 cylinder, a 37 mbar regulator, BS 3212 flexible armoured hose, and having the complete installation certified by a CP44-qualified gas engineer before your first event. The conversion itself is straightforward for a qualified engineer and typically takes a single day, but the legal requirement is clear: no CP44 certificate, no trading at any licensed market, festival or street food event in the UK.
LPG is the standard fuel for mobile catering in the UK for good reason. A propane G31 cylinder, a CP44-certified gas installation, and the right appliance connections gives you full independence from mains electricity, consistent heat output across a long service, and the ability to run anywhere — from a city market pitch to a remote agricultural show. This guide covers every component you need, what a conversion costs, how to find the right engineer, and the answers to the questions every new mobile caterer asks before their first gas inspection.
What Converting a Food Van to LPG Actually Involves
An LPG conversion for a catering van is not a mechanical conversion in the sense of modifying an engine. It means designing and installing a complete gas supply system inside the vehicle: from the cylinder storage point through to the appliance connections at each piece of cooking equipment.
A CP44-qualified engineer will assess your van layout, specify the correct regulator and hose sizes for your appliance load, install any required safety devices (overpressure shut-off valves, emergency isolation), fit appropriate ventilation panels, and then pressure-test the entire system before issuing your CP44 certificate.
The CP44 certificate is the document that proves your gas installation was designed and fitted correctly. Most event organisers, councils and market operators ask to see it before you trade. It is not a one-off — it needs renewing annually.
The Equipment You Need for an LPG Installation
A correctly specified LPG installation in a UK catering van requires the following components:
- Propane G31 cylinders: The standard for mobile catering. Propane vaporises reliably down to around -40°C, making it the only practical choice for outdoor UK operation. Butane is not suitable — it stops vaporising below approximately 5°C. For a busy van, two 13 kg cylinders with an automatic changeover valve allows uninterrupted service when one cylinder empties mid-shift.
- Automatic changeover valve: Switches automatically from the depleted cylinder to the full one without interrupting gas supply. An automatic LPG changeover valve with OPSO (over-pressure shut-off) is the standard fitting for a two-cylinder catering setup.
- 37 mbar regulator: All UK catering appliances are rated for 37 mbar (G31 propane). Do not mix this with a 28 mbar butane regulator — the fittings are different and the pressures are incompatible.
- BS 3212 armoured flexible hose: The correct flexible hose specification for a UK LPG installation. Must be replaced every five years as a minimum, or sooner if there is any visible damage, cracking or kinking.
- OPSO (Over-Pressure Shut-Off) device: A safety valve that cuts the gas supply if downstream pressure exceeds the rated limit. Required by most insurers and event organisations, and included in a properly specified installation.
- Drop-out ventilation panel: LPG is heavier than air and sinks to the floor. Catering vans require a low-level ventilation opening (typically the lower edge of the serving hatch or a dedicated floor-level vent) so any gas leak dissipates safely rather than accumulating under your appliances.
- Emergency isolation valve: An accessible shut-off valve that allows you — or an emergency responder — to immediately cut the gas supply. Must be clearly labelled and reachable from outside the cooking area.
Finding a CP44-Qualified Gas Engineer
Only an engineer holding the CP44 certificate of competence (or equivalent LPG vehicle qualification) can legally design, install and certify a gas system in a catering vehicle. This is different from a domestic Gas Safe engineer — the CP44 qualification is specific to LPG systems in mobile and portable catering applications.
To find a qualified engineer:
- Search the LPGA (Liquid Petroleum Gas Association) register of approved installers at lpga.co.uk
- Ask other mobile traders in your area — CP44 engineers who specialise in catering vehicles are well known within the street food community
- Contact your local mobile catering association or street food network for recommendations
- Some catering van builders include the CP44 installation and certification in the build price — worth asking if you are buying a new unit
See our complete guide to CP44 gas safety certification for mobile caterers for a full breakdown of what the certificate covers, what an engineer inspects, and what to do if your installation fails.
What Does an LPG Conversion Cost?
Typical costs for a complete LPG installation and CP44 certification in a UK catering van:
| Item | Typical Cost |
|---|---|
| CP44 engineer labour (installation + certification) | £300 – £600 |
| Regulators, hoses, fittings, OPSO valve | £80 – £200 |
| Automatic changeover valve | £40 – £80 |
| Ventilation modifications (if required) | £50 – £150 |
| Annual re-certification (inspection only) | £100 – £200 |
| Total first-year installation | £470 – £1,030 |
Costs vary depending on your van’s existing layout, the number of appliances being connected, and whether any structural modifications are needed. Vans that already have cylinder storage lockers and ventilation panels installed are significantly cheaper to certify than a bare shell conversion.
What the CP44 Engineer Inspects
When your CP44 engineer attends for the annual recertification, they will check:
- Condition and age of all flexible hoses (replace if over 5 years, cracked or kinked)
- Regulator condition and correct pressure output
- OPSO and emergency isolation valve function
- Ventilation — drop-out panel clear, unobstructed, correctly positioned
- All appliance connections — tight, no cross-threading, correct fittings
- Cylinder storage — cylinders upright, secured, not in an enclosed unventilated space
- Pressure test of the complete system to confirm no leaks
If any item fails, the engineer will not issue the certificate until it is rectified. Common failures are degraded hoses (the most frequent), blocked ventilation panels, and unsecured cylinders.
Frequently Asked Questions: Converting a Food Van to LPG
What does converting a food van to LPG involve?
Converting a food van to LPG means designing and fitting a complete gas supply system: propane cylinder storage, a 37 mbar regulator, BS 3212 armoured hose, an OPSO safety valve, emergency isolation, and proper drop-out ventilation. The installation must be completed by a CP44-qualified gas engineer who will pressure-test the system and issue a CP44 certificate of compliance. Without this certificate you cannot legally trade at events, markets or licensed pitches in the UK.
What equipment do I need for an LPG installation in a catering van?
The core components of a legal LPG installation in a UK catering van are: two propane G31 cylinders (13 kg is the most common size), an automatic changeover valve, a 37 mbar regulator, BS 3212 armoured flexible hose, an OPSO over-pressure shut-off device, an accessible emergency isolation valve, and a low-level drop-out ventilation panel. Your CP44 engineer will specify the exact fittings and sizes based on your appliance load and van layout.
What size LPG cylinder do I need for a catering van?
For most mobile catering vans, two 13 kg propane cylinders connected via an automatic changeover valve is the standard setup. A 13 kg cylinder provides roughly 6–8 hours of service under typical cooking loads depending on your appliances. Busier setups running multiple burners — fryers, grills, boilers — may need 19 kg cylinders. Your CP44 engineer will calculate the correct cylinder size based on your total gas consumption (MJ/h) across all connected appliances.
How much does it cost to convert a food van to LPG?
A complete LPG installation including CP44 certification typically costs £470–£1,030 for a UK catering van, depending on layout complexity and number of appliances. This breaks down as: engineer labour and certification (£300–£600), components including regulator, hose, OPSO and fittings (£80–£200), and any ventilation modifications required (£50–£150). Annual re-certification for an existing installation costs £100–£200. The equipment cost is recovered quickly — one busy market weekend typically generates enough revenue to cover the full installation.
Do I need a CP44 certificate to run LPG in a catering van?
Yes. Any LPG installation in a mobile catering vehicle must be certified by a CP44-qualified engineer before use at public events. The CP44 certificate covers the entire gas system — cylinders, regulator, hose, fittings, ventilation and appliances. Most event organisers, councils and market operators require a valid, in-date CP44 certificate as a condition of your pitch. Operating without one may also void your public liability insurance. See our full CP44 gas safety certification guide for complete requirements.
Can I use butane instead of propane in my catering van?
No. Butane is not suitable for mobile catering in the UK. It stops vaporising reliably at approximately 5°C, which means it effectively stops working on any cool day — and in a UK outdoor setting, that is half the year. Propane (G31) vaporises reliably down to around -40°C and is the correct fuel for all mobile catering applications. All UK catering appliances rated for LPG are designed for propane at 37 mbar. Using butane risks inconsistent gas pressure, appliance cut-outs mid-service, and potential safety issues.
How often does an LPG installation in a catering van need to be recertified?
An LPG installation in a mobile catering van must be recertified annually by a CP44-qualified engineer. The annual inspection checks hose condition and age, regulator function, OPSO and emergency valve operation, ventilation, appliance connections and a full pressure test. Hoses must be replaced at least every five years regardless of appearance. Most mobile caterers build the annual CP44 inspection into their spring pre-season service — alongside vehicle MOT and food hygiene renewal — so they start the outdoor season fully compliant.
Related Pages
If you found this guide useful, these pages cover related topics for mobile catering traders:
- CP44 Gas Safety Certificate Guide — what the inspection covers, how to find an engineer and what happens if you fail
- Automatic LPG Changeover Valve with OPSO — the standard fitting for a two-cylinder catering van setup
- Gas Water Boilers for Mobile Catering Vans — LPG hot water options for your van installation
- Mobile Catering Equipment Guide — complete checklist of what you need to set up a catering van
- Generator Guide for Mobile Catering — if you also need electrical power alongside your LPG setup