Blanking & Body Forming Line

In the core of the forming line there stands a versatile double action BNH LPG CYLINDERS L.L.P hydraulic deep drawing press that forms the cylinder halves out of round blanks that are blanked by a single action double blanking BNH LPG CYLINDERS L.L.P press or directly from the coil material by help of BNH LPG CYLINDERS L.L.P design combined deep drawing, piercing and blanking die set. The edges of the upper and lower halves are further processed by BNH LPG CYLINDERS L.L.P trimming and joggling machines to the perfection stemming from the sheet metal forming expertise of BNH LPG CYLINDERS L.L.P to make it read for the body seam welding after degreasing.

Welding, Heat Treatment and 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 wielding of the valve boss to the upper cylinder halve. The welding automats with reliable welding power packs and control units are utilized to achieve the uncompromising weld quality with degree of automation needed for the required production capacity per customer. The MIG/MAG welding technique is applied for the welding of foot rings and valve guard rings with the body halves.
In order to relive all the stresses caused by forming and welding operations, the cylinders are passed through a heat treatment furnace where they are exposed to 930 º C degrees of temperature for certain time before getting cooled gradually.

Valve Guard Ring & Foot Ring Production Line

LPG Cylinder valves BNH LPG CYLINDERS L.L.P offer complete production lines for all types of gas bottle valves. All the required equipment such as the induction heater, the forging press, the flash trimming press, the shot blasting machine, transfer machines to manufacture valve body pieces, the CNC lathes for smaller valve pieces and the washing machine can be supplied by BNH LPG CYLINDERS L.L.P. We supply turnkey production line machines with the engineering for the tooling and die sets specifically designed for particular valves. The valve pieces are assembled on the assembly and testing line where operational turn on turn off pressure levels and safety release pressure levels are adjusted, set and tested as per applicable international standards.

Production Process

The valve body is made out of brass bars by forging and machining. The bars are cut to required length by the saw and fed to the induction heater to heat up before forged under the forging press. After the forging and trimming operations the pre-forms are shot blasted and machined in the transfer machines and washed and dried to remove the chips. The plastic seat holder and spindle guide are manufactured by the plastic injection machine equipped with proper multi cavity die sets. The spindle parts and the retaining and adjustment screws are manufactured by the CNC lathes automatically fed by the bar feeders and washed in washing and drying machine. The valve pieces are assembled and leak tested and lock pinned on the assembly & testing line benches after manufacturing.

Valve Neck (Valve Boss or Neck Ring) Production Line

The steel rods of the neck ring start off material are first cut in required dimensions by saw, the pieces are induction heated up to forging temperature of 1200°C, de-scaled by de-scaling hammers and forged under the forging press in the die sets to get the performs to be further processed by flash trimming and hole piercing operation followed by the precise turning operation to get the final shape with valve threads.

Production Process

The bar is cut to required length by the saw and fed to the induction heater to heat up to forging temperature. After de-scaling and forging, the trimming and hole punching is achieved before the machining operation on the CNC lathes to give the final shape and cut the threads.

High pressure gas cylinders can range in size from a few liters to over one hundred, and they fulfill a wide variety of functions whether as medical or industrial gas tanks, accumulator shells, CNG containers onboard natural gas vehicles or SCUBA diver tubes. One thing, however, they all have in common: production quality is of utmost importance, because lives can depend on the integrity of a gas cylinder.

Surface Coating Line

The LPG cylinders surfaces are shot blasted by the shot blasting machine in order to clean up the scales caused by the heat treatment operation to make the surface ready for the painting and or zinc spraying for those customers who requires zinc coating before painting. The double layer over cured painting of the cylinders is achieved automatically by the robotic paint application system in the painting line as the cylinders conveyed on 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.
One of the batch type quality control equipment called by the international standards is the burst expansion testing unit where the volumetric expansion ratio and the burst pressure is measured to the full satisfaction of even most stringent requirements.

Finishing Line with Pneumatic Testing

The Pneumatic Testing Unit utilizes necessary equipment to apply and maintain the pressurized air into the cylinders. The pressure is applied for two minutes (adjustable) and any leakage is sought visually on the dashboard gauges.

Pneumatic Testing Unit has following properties