Commercial Gas Pipeline Installers
Cape Town

Gas pipework is the part of a commercial installation that nobody looks at until something goes wrong with it. It also determines whether the rest of the system can do its job: the best cylinder bank and the best appliances will still underperform if the pipe between them is undersized, badly routed or leaking at a joint.

Below: new gas lines, extensions to existing lines, alterations when a building layout changes, and the testing that proves the pipework is sound.

What Commercial Gas Pipeline Work Covers

• New gas lines from a cylinder bank, cylinder store or bulk tank to the point of use
• Pipeline extensions where a business adds equipment, a second kitchen, or a new production area
• Alterations and re-routing when walls move, a mezzanine goes in, or a tenant reconfigures a unit
• Riser installations taking gas to upper floors in multi-storey commercial buildings
• Buried and external runs across yards, service roads and between buildings on a site
• Manifold and header pipework connecting cylinder banks into a single supply
• Appliance connection points with isolation at each drop
• Decommissioning and safe removal of redundant runs

Pipe Materials Used on Commercial LPG Systems

Material choice depends on pressure, location, diameter and whether the run is internal, external or buried:

• Copper tube — common for internal runs at appliance pressure in kitchens and smaller commercial installations. Neat, straightforward to route around obstacles, and jointed by brazing or with approved compression fittings.
• Steel pipe — used for larger diameters, higher pressures, longer runs and anywhere the pipe needs mechanical robustness. Welded or threaded, and normally protected against corrosion where it is exposed to the elements.
• Corrugated stainless steel tube — flexible, quick to install through awkward routes and around structure, with fittings designed for the system. Useful in retrofits where a rigid run would mean opening up finishes.
• Polyethylene — used for buried external runs. It does not corrode in the ground, and it is transitioned to metallic pipe above ground at each end.

Whatever the material, pipework needs proper support at appropriate intervals, protection where it passes through walls, and sleeving through structure so the pipe is not in direct contact with the building fabric.

Pipe Sizing and Pressure Drop

Every metre of pipe, every bend and every fitting costs a small amount of pressure. Size the pipe correctly and the pressure at the furthest appliance is still within its operating range when everything is running. Size it too small and the appliances nearest the supply work fine while the ones at the end of the run suffer — which is why pressure faults so often appear to be an appliance problem rather than a pipe problem.

Sizing depends on four things:

• The gas flow required at peak demand, taken from the total connected load with a realistic diversity factor
• The length of the longest run from the regulator to the furthest appliance
• The number of bends, tees and fittings, each of which adds an equivalent length
• The operating pressure of the section, since higher pressure carries the same energy through a smaller pipe

This is also why extending an existing line is not simply a matter of adding pipe. The extension changes both the total load and the effective length, so the original section may no longer be adequate even though nothing about it has changed.

Two-Stage Pressure Systems

Most commercial LPG installations with any real pipe length use two stages of regulation:

1. 1First stage, at the storage. Cylinder or tank pressure varies with temperature and liquid level. The first stage regulator reduces it to a stable intermediate pressure.
2. 2The intermediate-pressure run. Gas travels to the building at this higher pressure, which means a smaller pipe can carry the same flow — a real cost saving on long runs.
3. 3Second stage, near the point of use. Pressure is reduced to appliance operating pressure close to the equipment, so appliances see a steady pressure regardless of demand upstream.

The alternative, running the whole distance at appliance pressure from a single regulator, needs a much larger pipe to avoid unacceptable pressure drop and leaves appliance pressure exposed to every change in demand along the line.

Routing Pipework Through a Commercial Building

Route decisions are where most of the site-specific cost and most of the practical difficulty sits:

• Keep runs visible and accessible where practical. Concealed pipework is harder to inspect and harder to test section by section when a fault appears.
• Avoid enclosed voids and unventilated ducts. Any leak in an unventilated void has nowhere to disperse to, and LPG will settle at the lowest point.
• Sleeve and seal wall penetrations, particularly through fire compartment walls, where the penetration has to be made good to maintain the fire rating.
• Protect pipework from impact in yards, delivery areas, loading bays and anywhere forklifts or trolleys operate.
• Allow for expansion on long external runs exposed to temperature swings.
• Do not run gas through electrical rooms, switch rooms or lift shafts.
• Label the pipework so it is identifiable to anyone working on the building later.

In Cape Town, external runs also need to be specified with the coastal environment in mind — salt-laden air is unforgiving on unprotected steel, and corrosion protection on exterior pipework is not an optional extra on sites near the sea.

Extensions and Alterations to an Existing Line

Businesses change and gas systems have to follow. The common triggers are adding equipment, converting a storeroom into production space, subdividing a unit for a new tenant, or relocating a kitchen within a building.

The work follows a fixed sequence:

• Survey the existing installation and confirm what is actually there against any drawings
• Recalculate the total load including the new demand
• Confirm whether the existing sections and regulators can carry it, or need upgrading
• Isolate, install the new section and make the tie-in
• Test the whole altered installation, not just the new part
• Re-certify the installation as altered

Testing the whole system rather than only the new pipework matters, because an alteration disturbs existing joints and because the certificate covers the installation as a whole. Certification after alteration is covered on the commercial gas COC Cape Town page.

Appliance Connection Points and Isolation

Each appliance takes off the line at a drop that includes an isolation valve, a connection suited to the appliance, and, where equipment moves for cleaning, a flexible connector with a restraint. Good practice is one isolation point per appliance plus a line isolation valve for the whole kitchen or production area, so a single machine can be taken out of service without shutting everything down.

Test points on the line let working pressure be measured without breaking joints, which makes future fault-finding much faster.

Pressure Testing and Leak Testing Pipework

Pipework is proven before it is put into service and again after any alteration:

• Strength testing confirms the pipework and joints withstand pressure above normal operating pressure.
• Tightness testing holds the isolated system at a set pressure and monitors for any drop over a defined period. A stable gauge means no detectable leak; a falling gauge means there is one to find.
• Sectional testing isolates the system in parts to narrow down where a drop is coming from, which is far quicker than inspecting an entire run.
• Joint testing with leak detection fluid or an electronic detector confirms the specific location once the section is identified.
• Purging displaces air from the pipework before appliances are commissioned.

For an existing system where a leak is suspected rather than a new installation being proven, see commercial gas leak detection in Cape Town.

Commercial Gas Pipeline Costs in Cape Town

A dimensioned site sketch showing the storage position, the building and roughly where the equipment sits will get you far more accurate quotes than a description over the phone.

Services That Work Alongside Pipeline Installation

Running a new line, extending an existing one or re-routing around a building change? Get quotes from commercial gas installers in Cape Town with the sizing calculated for your actual load.

Commercial Gas Pipeline Installers FAQs