Modern Air Cylinder Manufacturing Technology

Key Manufacturing Processes

Cooking cylinder production is done within the guidelines of the international standards such as EN 1442. It involves several process as listed below:
– Blanking & Body Forming
– Valve Guard Ring & Foot Ring Production
– Valve Neck (Valve Boss or Neck Ring) Production
– Welding, Heat Treatment and Hydrostatic Testing
– Surface Coating
– Finishing Line with Pneumatic Testing
– Valve Production
Cooking Cylinder Production is composed of several sheet metal forming, surface treatment and testing processes. The process starts with blanking, deep drawing and piercing, trimming and joggling. Next are the welding operations for valve boss, valve guard ring, foot ring and the two halves. The finished cylinder is then heat treated, tested, shot blasted, painted and then the valve is attached and final tested.

Blanking and body forming

In the core of the forming line there stands a versatile double action hydraulic deep drawing press that forms the cylinder halves out of round blanks that are blanked by a double blanking press. The edges of the upper and lower halves are further processed by trimming and joggling machines to the perfection stemming from the sheet metal forming expertise to make them ready for the body seam welding, with or without degreasing.

Foot ring (base ring) and valve guard ring (collar) production

Starting either from coiled strip material or already cut sheet steel plate strips, the different shapes of foot rings and valve guard rings require different process steps, different forming machines and different die sets all designed and manufactured in implacable adequacy. The typical process steps involves logo embossing and production data marking under single action hydraulic presses, serial number marking by hydro-pneumatic marking units, blanking of foot ring and valve guard ring blanks, round bending of the blanks, MIG/MAG welding of the foot ring blanks and forming of the final shapes using precisely engineered forming die sets under forming presses to ensure the welding quality in the welding line.

Welding, heat treatment & hydrostatic testing line

The submerged arc welding technique is applied on the welding of body halves on the seam welding machine and generally on the welding of the valve boss to the upper cylinder half.
In order to relieve all the stresses caused by forming and welding operations, the cylinders are passed through a heat treatment furnace where they are heated up to 930º C degrees of temperature for certain time before getting cooled gradually.
The hydrostatic testing of the heat treated Cooking Cylinders can be done on automated carousel type machines or on fixed station type machines to increase the internal pressure up to 35 bars for visual inspection as per requirements of the cylinder design specifications.

Surface coating & finishing line

The Cooking Cylinder surfaces are shot blasted by the shot blasting machine in order to clean up the scales caused by the heat treatment operation to prepare the surface for the painting and /or zinc spraying.
The double layer oven cured painting of the cylinders is achieved automatically by the robotic paint application system in the painting line as the cylinders are conveyed on an overhead conveyor system through the primary and final coat painting cabinets separated by flash off tunnels before they get cured in the canopy type modern paint curing oven.
After the tare weighing and marking of the cylinders, the valves are attached by automatic torque controlled screwing machines and tested against any leakage at the valve region by the pneumatic leakage testing machine of the finishing line.

Cooking cylinder valve production

The valves of Cooking Cylinders are made out of brass material by forging. The valve pieces are assembled on the assembly and testing line where operational turn on turns off pressure levels and safety release pressure levels are adjusted, set and tested as per applicable international standards.