LPG Bobtail Trucks: New vs Used Buying Guide
Buying an LPG bobtail truck? Compare new vs used, see the used inspection checklist, ADR checks and documents to demand before you commit.
6 min read
A used LPG bobtail can be a sound purchase when the tank passes inspection, non-destructive testing (NDT) and pressure testing, the ADR periodic inspection is valid with a known next date, and the metering, pump and chassis are in working order with a complete document file. New bobtails offer the latest specification but need months of build time.
This guide is written for fleet managers and distributors choosing between a new build and a certified second-hand bobtail. It covers the capacity and equipment that define a bobtail, the exact checks to run on a used unit, and the ADR and paperwork that must come with it.
KAF Cryogenics supplies LPG delivery equipment new to specification and as certified second-hand units, and also buys used equipment and accepts trade-in on new orders.
What is an LPG bobtail and what equipment defines it?
A bobtail is a truck-mounted LPG delivery tank used for short-haul, multi-drop delivery to tanks at homes, businesses and stations. Unlike a semi-trailer, the tank is built onto the truck chassis, which suits frequent stops on a delivery round. The delivery equipment on the tank is what makes it a bobtail rather than a plain tank.
Key components to assess on any bobtail, new or used:
- The pressure vessel tank, rated for LPG vapour pressure and coded to ASME or PED for the market.
- The delivery pump that transfers liquid LPG into the customer's tank.
- The metering system that measures delivered volume for billing.
- Hoses, reel, delivery valves and the emergency shutoff system.
- Gauging, the fixed maximum fill device and relief valves.
- The truck chassis, drivetrain and mounting.
New vs used LPG bobtail: how do they compare?
The decision comes down to lead time, budget, specification and risk. Neither is automatically better. The right choice depends on how soon you need the unit and how you weigh upfront cost against a newer specification.
- Lead time: a new bobtail is built to order over months. A certified second-hand unit can ship from stock in weeks.
- Cost: a used unit generally carries a lower purchase price, though condition and remaining service life vary.
- Specification: a new build lets you choose tank size, pump, meter and chassis exactly. A used unit is what it is, so match it to your route.
- Risk: a new unit comes with full manufacturer documents. A used unit is only as safe as its inspection, testing and paperwork, which is why the checks below matter.
- Warranty: KAF sells certified second-hand units with a written warranty, which narrows the risk gap against new.
What should you inspect on a used LPG bobtail?
Treat a used bobtail as two purchases in one: a pressure vessel and a road vehicle. Both must be checked. A certified second-hand unit from KAF has already passed this process, but any buyer should know what a proper inspection covers.
Tank and pressure vessel checks
- Visual inspection of the tank shell, heads and welds for corrosion, dents, gouges or repairs.
- Non-destructive testing (NDT) of welds and shell to confirm integrity without cutting the vessel.
- Pressure test records confirming the vessel holds its design pressure.
- Nameplate check for water capacity, design pressure, design temperature and code stamp.
- Relief valve condition and test or replacement date.
- Gauging and the fixed maximum fill device for correct operation.
Delivery equipment checks
- Pump operation, seals and leaks under load.
- Meter accuracy and calibration record, since billing depends on it.
- Hoses, reel, couplings and delivery valves for wear and certification date.
- Emergency shutoff and remote controls for correct function.
Chassis and vehicle checks
- Chassis condition, mounting and structural corrosion.
- Roadworthiness of the drivetrain, brakes and tyres.
- Odometer, service history and any accident record.
Why does ADR matter when buying a used LPG bobtail?
ADR is the European agreement governing the international road transport of dangerous goods, and LPG delivery vehicles fall under it. An LPG road tanker must pass periodic ADR inspection to stay in service, and the inspection confirms the tank, fittings and safety equipment remain compliant.
When buying used, a valid ADR certificate with a known next inspection date directly affects the value and the time before you must present the unit for reinspection. A bobtail with a lapsed or soon-to-expire ADR date may need work and recertification before it can legally operate, so confirm the date in writing before you commit.
- Confirm the ADR certificate is present and valid.
- Note the next periodic inspection date and factor it into your schedule.
- Check that tank markings, plates and safety equipment match the certificate.
- Ask whether recent ADR work or repairs were carried out and get the records.
What documents must come with an LPG bobtail?
A bobtail without its paperwork is difficult to value, insure and operate. Demand the full document dossier and verify it against the nameplate and ADR plate on the unit.
- Pressure vessel code certificate, ASME or PED as applicable.
- Manufacturer data report and design details.
- NDT and inspection reports for a used tank.
- Pressure test records.
- Valid ADR periodic inspection certificate with the next due date.
- Meter calibration certificate.
- Vehicle registration and service history.
- For a certified second-hand unit, the written warranty.
How does capacity and route affect the bobtail you choose?
Match tank capacity to your delivery round. A bobtail on a dense urban route with many small drops behaves differently from one covering longer distances to fewer, larger customers. Larger capacity means fewer returns to the depot per shift but a heavier, less nimble vehicle.
Consider the size of the customer tanks you serve, the axle and weight limits on your routes, and how many drops a single fill should cover. For long-haul bulk movement between depots, a semi-trailer or ISO tank may fit better than a bobtail.
Should you trade in an old bobtail when you upgrade?
If you are replacing an ageing bobtail, its residual value can offset the next purchase. KAF buys used equipment and accepts trade-in against a new order, so an old but serviceable unit does not have to sit idle.
Units keep more value when they come with a complete document file, a valid ADR certificate, calibration records and evidence of maintenance. Keeping the paperwork in order through the vehicle's life pays back at resale or trade-in.
Frequently Asked Questions
Is a used LPG bobtail safe to buy?
Yes, when the tank has passed inspection, NDT and pressure testing, the ADR periodic inspection is valid, and the pump, meter and chassis are in working order with complete documents. A certified second-hand unit sold with a written warranty and a document dossier reduces the buyer's risk considerably.
What is the most important check on a used bobtail?
There is no single check. Treat it as a pressure vessel and a road vehicle together. The tank needs visual inspection, NDT and pressure test evidence, the ADR certificate must be valid with a known next date, and the pump, meter and chassis must function. Missing paperwork is a warning sign.
How often does an LPG bobtail need ADR inspection?
LPG road tankers undergo periodic ADR inspection to remain in service, and the certificate carries a next due date. When buying used, confirm the certificate is valid and note that date, because a lapsed ADR inspection can stop the unit from operating until it is recertified.
How much faster is a certified used bobtail than a new build?
A new bobtail is built to order over months. A certified second-hand unit that matches your requirement can ship from stock in weeks. When you need to add delivery capacity quickly, the stock route shortens the timeline significantly.
Why does meter calibration matter on a used bobtail?
The meter measures the LPG delivered to each customer, so billing accuracy depends on it. Ask for the calibration certificate and confirm it is current. A meter that reads incorrectly costs money on every delivery, in one direction or the other.
Can I trade in my old bobtail against a new one?
Yes. KAF buys used LPG equipment and accepts trade-in against a new order. A serviceable unit with complete documents, a valid ADR certificate and maintenance records holds more trade-in value.
Related reading
Buying or replacing an LPG bobtail?
Tell KAF your route, capacity and timeline. We can quote a new build to specification or supply a certified second-hand bobtail from stock, inspected, NDT and pressure tested, with a document dossier and written warranty. Trade-in on your old unit is available.
Talk to KAF