General Description
The Gas Distribution System was developed in close cooperation with the Norwegian Maritime Authorities. Today it forms part of the rules and regulations for handling such gases.

Several other shipping nations have adopted the system for installation on board ships under their flags.

All components are carefully selected for the specific conditions found on board. The design ensures full compatibility between components, with the Unitor gas cylinders and the rest of the gas welding/cutting equipment available from Unitor.

Wilhemsen Ships Service AS at Your Service
Wilhelmsen Ships Service AS, as the world’s leading maritime specialist in this field, offers the following essentials to ensure optimal operational conditions:

1. The design and drawing of suitable systems which will be approved by the relevant classification society.
2. Contacting the proper Authorities and securing of all necessary approvals.
3. Installation of plant and equipment.
4. Commisioning and issueing of certificates.

Complete after-installation service, including spare parts and maintenance programmes worldwide, plus gas cylinder exchange.

All the above essential services are provided by our highly trained technical team which is available, together with any additional information required, from Unitor’s Head

Deciding number of cylinders to be connected
An Acetylene cylinder should normally not be emptied faster than 700 l/h to avoid acetone withdrawal of the gas. This is sufficient for most normal welding and cutting work with one operator, but insufficient for larger operations as for example heating with the larger blowpipes, or gouging. To ensure full work flexibility, a minimum of two Acetylene cylinders should therefore be connected to the system.

As the average Oxygen consumption is twice that of Acetylene the corresponding number of Oxygen cylinders connected should be four.

The 2 Acetylene plus 4 Oxygen cylinder central is sufficient for two operators doing normal gas welding or cutting work, or for one operator doing larger heating work. Hence it will be a suitable solution for a gas distribution system with up to two outlets. If more than two outlets are required, and it is expected that more than two operators will be working at the same time, one Acetylene and two Oxygen cylinders should be added per operator.

Total number of cylinders on board
The contents of an A-40 cylinder is 5600 l. This is sufficient for a minimum of:

8-9 hours of brazing or welding (650 l/h)
or 3 1/2 hours of heating (1650 l/h)
or 7 hours of cutting (810 l/h).

Recommended number of cylinders in stock on board, including the cylinders in the gas central, must thus be decided on basis of how many man-hours of work involving welding processes are necessary to be prepared for. In the following table one work day equals 8 man-hours.

For special repairs the gas quantities should be calculated based on the consumption rates which will be listed in the instruction manual for your welding equipment.