Production Process

At the beginning

EVAS, address of high quality LPG Cylinders, maintains its main target – customer satisfaction – by the following steps;

All raw materials like metal sheets, fluxes, welding wires, paint and semi finished products like valve guards, foot-rings, valves are accepted to production area after the control which is realized according to related Incoming Material Quality Control Plan. EVAS, arranges its facilities and procedures to not allow any raw material or semi finished product that is not accepted by Income Quality Control Department.

Cylinders depending on their capacities are manufactured from two or three pieces. During the production of two pieces cylinder, two halves are produced with deep drawing process by hydraulic presses. After skirts are cut, trimmed and joggle-joint formed, halves also valve guards and foot-rings are routed into washing unit where they are pickled with chemicals then washed and dried to prevent the harmful contaminated that may be caused by press operation.


After the cleaning of parts, valve boss, valve guards and foot-rings are welded in the automatic gas shielded arc welding process (MAG). Fitted drawn halves are welded by a single pass circumferential welded lap in the automatic submerged welding machines to obtain sound weld with deep penetration. All welding operations are performed according to welding procedures by certificated welders. Additionally, all welding parameters are simultaneously followed by engineers from the monitors and recorded into computers.

High capacity cylinders are fabricated from three pieces. Such a cylinder consists of cylindrical shell rolled and butt welded in automatic submerged metal arc process longitudinally and two deep drawn heads skirts cut, trimmed and joggle-joint formed are connected to the shell circumferentially by automatic submerged arc welding process.
In the middle

After the welding operations cylinders are normalized, where material regains original properties, in a proud of EVAS, the first in the world automatic loading and unloading, of the LPG cylinders digitally controlled and continuously temperature recorded furnace. Cylinders are uniformly heated without direct contact with fire and depending on material and thickness, traveling speed of cylinders through furnace and heating, soaking and cooling cycle periods and temperatures can be adjusted to restore the material into the original mechanical conditions.

After the normalization process, all cylinders are hydrostatically tested depends on the content of the cylinder (Butane, Propane, Mixture).

In order to achieve good bonding for Zinc or anti-rust paint primary coating, each cylinder surface is externally blasted with the ball – grit mixture until clean white metal surface is obtained. Also cylinders are heated before zinc coating.

Zinc coating is applied immediately after the shot-blasting in the Fully Automatic Metal Arc Spraying Cabin. By this system, uniform and good adhered Zinc coating is obtained.

EVAS has a capability to apply double layer wet paint or powder paint, or combination of them in accordance with customer demand. Besides that all multi color application requests are welcome.

At the end

Following to painting process serigraphy is applied onto the cylinders respected to the customers demand.
Prior to valve fitting process threads are cleaned to remove possible grit, zinc, paint and other foreign material. Valves are fitted to cylinders by the help of PLC controlled machined and all torque values are recorded. Following to valve fitting, cylinders are applied to leakage test at minimum 6 bars. Then cylinders are consecutively weighed twice on automatic devices and tare weight is written by inkjet printing system. Before the shipment, all cylinders are packed with bubbled bags or plastic nets to ensure secure delivery without damage.