LPG Reservoir / Vessel (LPG Vessel)

An LPG reservoir / vessel (LPG — liquefied petroleum gas) is a pressure vessel that stores the building's gas supply used for cooking, water heating or thermal processes, and feeds it into the gas piping system. It is a pressure vessel storing a flammable, asphyxiating gas, and for that reason it is subject in Israel to a periodic inspection by a qualified party — neglecting it can end in a leak, an explosion and a legal violation.

An LPG vessel is only one item among the dozens of systems every building must maintain on a fixed cycle. The right way to manage them all together is a preventive maintenance program — see the complete PPM guide.

How the system works

LPG is stored in the vessel in liquid form under pressure — a small volume of liquid holds a large amount of energy. When the outlet valve is opened, part of the liquid vaporizes inside the vessel and flows out as gas. A pressure regulator reduces the vessel's high pressure to a low, stable working pressure that the building's piping and appliances can accept, and from there the gas flows through the piping to the points of consumption.

The vessel is not "just a tank": it carries a relief valve that releases gas if the internal pressure rises above the permitted level (for example in extreme heat), a content/pressure gauge, isolation valves, and detectors/safety measures appropriate to the installation. An above-ground vessel is exposed to solar radiation and external impact and is therefore positioned, fenced and ventilated according to the installation rules. The vessel is only the storage heart of the LPG installation — the piping, regulators, isolation valves and connection to appliances are a separate part of the installation and are inspected separately.

Why the system is necessary + risks of neglect

An LPG vessel provides the building with an independent energy source for cooking and heating — but the very property that makes it useful (dense energy storage under pressure) makes it dangerous when neglected. LPG is heavier than air, so a leak sinks and accumulates in low spaces, pits and underground stairwells, creating an explosive mixture that a small spark is enough to ignite. Corrosion in the vessel wall, a stuck relief valve, a faulty regulator or a leaking connection — any of these can turn a silent leak into a destructive event.

Beyond safety, an LPG vessel is an installation subject to a statutory inspection obligation. A vessel without a valid periodic inspection is a violation that can trigger personal liability of the building manager/occupier, denial of insurance coverage in the event of damage, and prosecution by the authorities. Neglect here is not a saving — it is a direct safety, legal and insurance exposure, and at times also grounds for cutting off the gas supply.

The maintenance regime — what, how often, and how

Under Domera's PPM matrix, which is based on the Israeli inspection requirements, the mandatory inspection of the vessel is:

• LPG reservoir inspection — periodic Type 1 inspection: a cycle of five years (60 months). This is a periodic Type 1 inspection for above-ground LPG vessels, as it appears in the inspection requirement. This is a statutory requirement applying to every site where such a vessel is installed.
• Performing party: an LPG installer — who carries out the periodic inspection and certifies the vessel's soundness.

Beyond the vessel's periodic inspection, the entire LPG installation around it (piping, regulators, tightness) is subject to its own inspection regime by an LPG installer. Between periodic inspections, the routine maintenance team must verify that there is no gas smell, that the vessel area is fenced, ventilated and clear of flammable materials, that the signage is intact, and that there is no external corrosion or mechanical damage to the vessel and its fittings. Documenting these safety walkthroughs is part of the installation's operational discipline. Additional frequencies and conditions beyond the above — per the current standard and the guidance of the authority/manufacturer; do not rely on estimation in place of the LPG installer's certification.

Who is qualified to maintain and certify

The periodic inspection of the LPG vessel and the certification of its soundness are within the authority of an LPG installer only. Do not settle for a general maintenance person, an appliance technician or the gas supplier for the statutory inspection: only a qualified LPG installer may carry out the periodic inspection and certify the continued use of the vessel. Routine visual maintenance and environmental control (fencing, ventilation, cleanliness, smell) may be performed by the maintenance team — but the legal certification of the vessel remains with the LPG installer.

Standards and regulation

An LPG vessel is included among the gas installations that require a periodic inspection by a qualified party within Israel's gas and safety regulation. The mandatory inspection of the vessel is a periodic Type 1 inspection for above-ground LPG vessels once every five years, by an LPG installer, and it is a statutory requirement applying to every site. The remaining details — the type of inspection according to the vessel, sub-frequencies and installation conditions — are determined per the current standard and the guidance of the authority/manufacturer and according to the type and size of the vessel; they must be verified with the LPG installer in each cycle and not relied upon as generic figures. (The inspections of the LPG installation itself are anchored in SI 158 part 4 — see the installation article.)

Required documentation and forms

The mandatory document to keep in the building file is the vessel's periodic inspection certificate, issued by the LPG installer and attesting to the performance of a valid periodic Type 1 inspection. Alongside the vessel certificate, the entire LPG installation is documented in the uniform gas annex — Form 18 (uniform gas annex) — which is the document that consolidates the gas installation details for fire and rescue safety purposes. It is recommended to also keep the vessel's name-plate with the pressure and volume data, the manufacturer's specification, and the documentation of the routine safety walkthroughs.

For the complete documentation picture of all the building's systems, see the PPM guide and the Knowledge Hub.

Common faults and warning signs

• A gas smell around the vessel — the most critical sign. It requires shutting off sources of fire/spark, ventilation, and an immediate call to an LPG installer; do not operate electrical switches.
• Corrosion, rust or mechanical damage to the vessel wall — thins the wall and endangers the integrity of the pressure vessel; requires an LPG installer's inspection.
• A stuck relief valve or a faulty regulator — may cause a dangerous rise in pressure or an unstable gas supply to appliances.
• A blocked, unventilated vessel area or one crowded with flammable materials — prevents the dispersal of a leak and increases the risk of ignition.
• Missing safety signage, a stuck content gauge or breached fencing — signs of operational neglect and an obstacle to emergency response.
• Expiry of the periodic inspection — a vessel without a valid certificate must not be used; an LPG installer's inspection must be arranged before the certificate expires.

The value of professional maintenance management / how Domera helps

An LPG vessel is a "quiet" installation that works in the background until a leak or an expired certificate turns it into a risk. The way to prevent this is discipline: inspection on time, with the right party, with a valid certifying document. Domera manages the vessel as an item in a PPM program: one open maintenance instance per program, closure only against an approved periodic inspection certificate, and an automatic reminder before the certificate expires — so that the vessel is never left a single day without a certificate. The compliance reports consolidate the vessel's status, the LPG installation and all the building's other systems in one place.

Frequently asked questions

What is an LPG reservoir / vessel and why is it considered a pressure vessel?

An LPG vessel is a tank that stores cooking gas (liquefied petroleum gas) in liquid form under pressure, and feeds it into the building's gas piping. Because it stores flammable gas under pressure, it is classified as a pressure vessel and requires a statutory periodic inspection.

How often must the LPG vessel be inspected?

A periodic Type 1 inspection for above-ground LPG vessels is required once every five years (60 months), by an LPG installer. This is a statutory requirement applying to every site where such a vessel is installed.

Who is qualified to inspect and certify an LPG vessel?

A qualified LPG installer only carries out the periodic inspection and certifies the vessel's soundness. A maintenance person or gas supplier may perform routine visual control, but they are not permitted to issue the periodic inspection certificate.

What is the difference between the LPG vessel and the LPG installation?

The vessel is the storage heart — it stores the gas and is inspected in a periodic Type 1 inspection every five years. The LPG installation is the surrounding piping, regulators and isolation valves, and it is inspected separately by an LPG installer per SI 158 part 4 (Form D4 / D5).

Which document must be kept in the building file?

The vessel's valid periodic inspection certificate, alongside the uniform gas annex (Form 18) that consolidates the gas installation details for fire safety purposes. It is recommended to also attach the vessel's name-plate and manufacturer's specification.

What do you do when you smell gas near the vessel?

Immediately shut off any source of fire or spark, avoid operating electrical switches, ventilate the area and call an LPG installer and the emergency services without delay. Do not continue using the installation until it has been inspected and certified.

Why is LPG especially dangerous in low spaces?

LPG is heavier than air, so a leak sinks and accumulates in pits, basements and underground rooms instead of dispersing. There an explosive mixture forms that a small spark is enough to ignite — which is why ventilation and correct positioning of the vessel are important.

Further reading

• LPG Installation — the piping, regulators and inspections of the gas installation surrounding the vessel (SI 158 part 4, Form D4/D5); the vessel's direct sister system.
• Uniform gas annex — Form 18 — the document that consolidates the gas installation details for fire and rescue safety purposes.
• The complete PPM guide — the process and full matrix that manage all the building's systems, including pressure vessels and gas installations.
• Domera's Knowledge Hub — all the building-systems articles in one place.