General Information :

Part-A Raw Material Testing  IS 6240
  • Chemical composition Requirement
  •  Material physical properties Requirement

PART-B : Prototype testing for design approval

  • Acceptance tests
  • Hydro-static stretch test
  • Hydro-static test
  • Burst  test
  •  Pneumatic leakage test
  • Radio graphic examination

Part- C : Inspection and Testing During Manufacturing :

  •  Raw material testing
  • Welding inspection
  • Agreed finished thickness test
  • Cylinder circularity
  • Surface defects examination of cylinder
  • Profile regularity of cylinder
  • Straightness of cylinder
  •  Verticality of cylinder
  • Inspection of all individual components like bung, valve protection and foot ring
  •  Water capacity
  • Radiography of welds, spot radiography
  • Hydro-static test
  •  Pneumatic test
  • Cycle or fatigue test
  • Inspection of certification markings

Part-D : Statutory Testing

In every manufacturing location, two cylinders picked randomly from a fresh manufacturing batch and are subjected to statutory testing. Among these two cylinders, one cylinder is subjected to acceptance test and the other is subjected to hydro-test.
Few additional tests / inspections are carried out on these cylinders along with acceptance and Hydro-tests and are water capacity test, thickness test, and pneumatic tests. Further, cyclic tests are to be carried out on few cylinders to check the acceptance of cylinder for cyclic tests. Thus the following are the critical tests for statuary approval

Burst Test and Nominal Hoop Stress :

General Information :

Based on the burst pressure nominal hoop stresses of a cylinder at burst pressure conditions are calculated

• Burst pressure (BP) : Min 54.92 Bar
• Nominal Hoop Stresses (NHS) : Minimum 332.5 Mpa

One cylinder from every manufactured lot of 403 and below should test for measuring burst pressure and nominal hoop stresses. Generally the cylinder tested for volumetric expansion test can be used for this purpose. In this test, cylinders are subjected to continuous hydro-static internal pressure till it bursts. The internal pressure of cylinder at which it bursts is noted and recorded as burst pressure. Based on this burst pressure nominal hoop stresses are calculated using below formula
fb=(Pb ×Di)/2t
fb-nominal hoop stress at which destruction occurs
Pb-Internal hydrostatic pressure at which cylinder bursts in MPa;
Di -Nominal original internal diameter of the cylinder in mm
t-minimum agreed finishing thickness of the cylinder in mm.

Test Parameters :

  • Max Test pressure : 160 Bar / 250 Bar
  •  No of test cylinders : 01 Nos
  •  Test Temperature : Ambient
  • Max cyl size :
  • Min cyl size :
  • Test duration : 2-3 min appx
  •  Type of test : burst pressure test

Main Equipment Consists of :

  • Burst Test Chamber
  • Pressurizing Unit
  • Local control Unit with PLC and HMI and electrical control panel.
  •  Centralized SCADA for Data Acquisition, report generation and trend display over computer pc
    ( Common for all test Lab equipment mentioned in the proposal )

Ancillary Equipment / Items required :

  • Cage to contain cylinder during testing
  • Clear Gap of at least 1 Mtr on all sides of test equipment for ease in maintenance
  • Low Pressure Air compressor for utility air

Display and Records :

  • Burst Test Pressure
  • Total time to burst / ramp rate
  • Test Medium Used
  •  Pressure v/s time graph


Water Jacket Method

IS 3196 PART-3 

One cylinder from every manufactured lot of 403 and below should undergo hydro-static stretch test

Standard allows permanent volumetric expansion of 1/20000 the total cylinder capacity.

Volumetric expansion (VE) : Should be greater or equal to 20 % ( for TS less than or equal to 410 Mpa )

Machine Selection criteria :

Test Pressure Requirement :

• MLPG : 25 Bar capacity Machine
• Stabilization/ Holding Time : Min 60 Sec

Technology Used :

• Power pack driven intensifier system : High cost system
• Air driven pump system : Low Cost system

Operational Interface :

• HMI control interface
• SCADA with Normal Grade computer
• SCADA with Industrial Grade computer
Test Parameters : ( IS 3196-1: 2006 )
• Max Test pressure : 25 Bar
• Holding for minimum 60 sec
• Measurement of expansion volume v/s pressure
• Measurement of expansion volume v/s time.
• No of test cylinders : 01 Nos
• Test Temperature : Ambient
• Max cyl size :
• Min cyl size :
• Test duration : 10 min appx including setting time
• Type of test : Volumetric Expansion / stretch test

Main Equipment Consists of :
• Heavy Duty Water Jacket system
• cylinder expansion measurement system
• Pressurizing Unit
• Local control Unit with PLC and HMI and electrical control panel
• Centralized SCADA for Data Acquisition, report generation and trend display over computer pc ( Common for all test Lab equipment mentioned in the proposal )
Ancillary Equipment / Items required :
• Lifting arrangement for jacket lid
• Clear Gap of at least 1 Mtr on all sides of test equipment for ease in maintenance
• Low Pressure Air compressor for utility air

• Maximum expansion volume of cylinder under test
• Residual expansion volume of cylinder under test
• Max pressure applied
• Percentage of stretch
• Test medium used
• Mode of failure
• Passed or Failed
• Expansion volume v/s pressure or expansion volume v/s time graph
Clamping Vice for Adaptor fixing with jacket Lid ( Customer Scope )

Water Jackets with built in safety system

Pre-filling system for water jacket and test cylinder :

High Pressure Generation System
Hydraulic power pack driven high pressure generation system with required controls is a highly reliable and maintenance free system today.
Power requirement will be 1 HP
Max water pressure will be 50 bar

Instrumentation controls
High precision, Imported, pressure transmitters for accurate pressure feedback

High precision, Digital scale for water volume measurement feedback

Auto cutoff valves for control of test parameters

Water filtration system for enhanced performance of water components

Automation & Electricals :

• Measurement of water volume before applying test pressure, after giving full value of set pressure as well as after releasing the test pressure.
• PLC system for controlling the operational sequence .Pressure Transmitter to record the pressure value.
• HMI for operation and viewing the test results for HMI machines ( HMI not required for SCADA based machines )
• Electric control panel with branded relays, contactors , signal conditioners, signal isolators and other required hardware
• Control panel with tube light, extra plug sockets, cooling fan, filters etc will be available by default.
• Schneider or equivalent brand high end PLC hardware with some spare IO’s will be designed and made available

Computer Registration / DAQ System ( Optional )

In SCADA system :

• Test results will be displayed on computer screen and test reports will be saved in computer hard disk at a predefined location in an excel or pdf format as per customers selection
• Customized Test reports with company name, logo , serial no, description etc will be designed for issuing test certificate with unique auto generated serial no to issue the test certificate to end customer.

• Optional Utilities such as data management software system as well as Management Reporting Module will be made available to customer at an additional cost as and when needed.

• Normal PC or IPC with IP65 protection will be available as per customer’s selection and shall be quoted separately

• Printer shall be quoted separately
• Overhead Water storage Tank to conduct the test, if required
• Initial Hydraulic oil filling at the time of commissioning.
• Power supply with stabilizer / UPS for computer system
• Utility such as air, water, electricity, earthing etc


Put the cylinder into a water jacket and pressurize the cylinder by high pressure pump; it will slowly dwell with the rise of pressure inside cylinder.
With expansion of main cylinder under pressure , the cylinder squeezes some water from water jacket into the measuring cup, and the water in the measuring cup now is the testing cylinder volume deformation, and then the water measurement data is transferred to PLC by water collection system;
The cylinder elastic deformation disappears after pressure releasing, then the water flows back from measuring cup to water jacket.
However, the remaining water in the measuring cup is still more than that before pressurizing the cylinder and the extra water volume is the testing cylinder volume residual deformation, and this measurement is transferred to computer through water collection system;
The gas cylinder permanent or residual deformation rate is the ratio of the total expansion- elastic expansion/ Total expansion
The Temperature during the test shall remain constant and hence density of water will also remain unchanged.

The following readings will be taken by computer.

1. Volume/ weight of water in the measuring cup before the test pressure has been applied : V1
2. Volume/ weight of water in the measuring cup after the test pressure has been applied for at least 60 sec : V2
3. Volume/ weight of water in the measuring cup after the test pressure has been released : V3

Total volumetric expansion = V2-V1
Permanent Expansion = V3-V1

This value should be within 1/5000 of the original volume of the cylinder

( Air Driven Pressure Pump System )

To reduce the capital investment, this option also is available
In this option, Air driven pump will be used for building up high water pressure.
Air driven high pressure pump for high pressure built up.
( A suitable air compressor, air receiver tank, air dryer and other required accessories for providing dry and lubricated air to drive the pump shall be arranged by customer )

( water line with proper filter and line pressure of at least 2 bar to be arranged by customer to nearby point of machine connection )



Time and air consumption :

The normal drive air pressure available in shop will be 5 to 6 bar and to reach the required output pressure of 300 bar will need intensification ratio of 60. This means plunder area is 60 times smaller than drive piston area. This will lead to a very small amount of discharge volume. The pressure rising time will be high and this leads to continuous consumption of drive air

power pack driven system will have intensification ratio of 3 to 4 only leading to high discharge volume available per stroke
Air Quality :

Air compressor, Air Receiver, Air cooler, Air Dryer, Air Filter , lubricator and regulator—needs to be installed and maintained in order to have a trouble free working of air driven pump.

Hydraulic power pack driven intensifier has oil cylinder on one part which is self lubricated hence maintenance free operation is ensured. No need of installing additional items to conduct the test. So independent of other ancillaries and no additional investment on such items required in this case.


Some equipment supplier expect customer to provide minimum 1 bar pressure water line. This wording removes many items from their scope of supply

1. Prefilling pump
2. Suction strainer
3. Outlet water filters- cartridge type
4. Safety bypass valve for pump
5. Water tank
6. Water tank drain valve
7. Water level control switch
8. Water tank float switch
9. Intermediate pipings

This helps to reduce the size of fabrication panel and associated cost

In powerpack driven system , all the above items are part of equipment supply


• Air Compressor
• Refrigerent Type Air Dryer
• Air Lubricator
• High Running cost for producing air as efficiency of compressor is almost 60 %
• Low Production Rate
• Arrangement of water pre-filling system with proper filtration arrangement

• The customer will need to provide water tapping line and Quality electric power line to the machine point
• All Other required items are included in the machine
• No additional investment needed to drive the high pressure pump
• Production rate is high
• Running / Operational cost is low


Fatigue test/cycle test :

Fatigue or cyclic test is a type test. This test is conducted under cyclic loads to check the fatigue strength of cylinder and cyclic pressures

Test Parameters :

  • No of cycles : 10000 cycles, frequency < 15 CPM,
  • Test pressure range : atm to 30 Bar
  •  No of cylinders : 02
  • No of Legs : 02
  • Test Temperature : Ambient
  • Max cyl size : As per customer requirement
  • Min cyl size : As per customer requirement
  • Test duration : Appx 15 hours
  • Type of test : pressure cycle test at ambient conditions
  • Test fluid : oil or water

Main Equipment Consists of :

  • Pressurizing Unit
  • Local control Unit with PLC and HMI and electrical control panel
  • Centralized SCADA for Data Acquisition, report generation and trend display over computer pc
    ( Common for all test Lab equipment mentioned in the proposal )

Ancillary Equipment / Items required :

  • Clear Gap of of appx 1 Mtr on all equipment for ease in maintenance
  • Low Pressure Air compressor for utility air for cleaning of floor area.
  • Oil chiller system to maintain the fluid temp within operational limits.

Display and Records :

  • Upper cycle Test Pressure
  • Lower cycle Test Pressure
  •  Cycle Frequency
  • No of cycles
  • Test Medium Used


Test setup for ambient cycle test consists of testing 2 test cylinders . The system will have a pressurizing unit for achieving required peak and base pressure and to detect failures when this occurs. Local control panels communicate with a central PC, which provides the data logging and reporting capability.

Cyclic Pressurizing Unit
The pressure system is a hydraulic based power pack, capable of supplying controlled pressure in a cyclic manner.
The system consists of an electrically driven hydraulic pump, pressure regulating system, pressure accumulators, hoses, sensors, electro valves and ancillary safety equipment.
Oil pressure is supplied to two oil/water separators. Separators are constructed with a special lining from inside to suit water used in testing.
Also supplied with the pressure testing system:
• Inlet water filter,
• High pressure hoses
• Distribution piping
• solenoid valve
• High precision pressure transducers
• Signal Conditioners, amplifiers and other hardware to interface the above components
with the PC data acquisition and control.
The combination of oil flow pump and attenuators provide a responsive supply of pressurized water while reducing the energy consumption and the wear and tear on the pump.
Local Control Unit :
A local control unit is to build the cyclic test pressure at the predetermined levels, to monitor cylinders and to report readings to the central control unit.
The local specimen control unit consists of an electric panel comprising a PLC and HMI and signal conditioning electronics.
Also supplied as part of the local control unit:
• Digital display of upper pressure, lower pressure, cycling frequency , no of cycles and status of test
• Outlets for additional calibration pressure transducer

Description of Operation:
This section describes operation of system to illustrate ease of use, and to show the interaction of the different components within the system:
• From PC, operator sets the test parameters including test ID, cylinder information, test conditions and no of cycles to be tested.
• Operator installs specimen, fills it with tap water, connects it to pressurizing unit and enables testing from the local control panel. As pressure starts to build up, air vent should be manually opened until air is purged from specimen. Test may be interrupted to attend to minor leaks, adjustments or until both specimens are ready to start.
• During test, the local control system automatically monitors and logs test data in real-time. Relevant information is displayed real-time on the HMI display and is sent to the PC for data logging and reporting. In case of PC failure or unavailability, data is stored locally until PC is re-connected.
• At termination of test, reports are displayed on PC.
Below are some important features of the long term testing system:
• Long-term stability.
• Data is saved on local unit until accessed by PC
• Handshake mode, central unit constantly monitors health of local units.
• Pressure sensors provided to match testing ranges.

General features of software include:
• Software package guides operator, performs calculations and reports results in accordance with corresponding standard requirements.
• System functions controlled from Virtual Control Panel on PC screen.
• Instantaneous on-screen displays of test data and curves during testing.
• Key parameters such as upper and lower cyclic pressure , cycle frequency , no of cycles etc. are displayed on screen. Also test reports are generated at end of test or termination of test.
• Test reports in accordance with client’s requirements, both in terms of contents and format (fonts, colors, Logo, etc.)
• Test results are stored in the QC laboratory database.
• Multiple test templates, enabling reports generation in different formats for the same test (company internal report, client report…)
Test Results:
• All test results are stored on the system in a database using a format accessible by different software, such as Excel, for further analysis or for inclusion into managerial reports.
• Test reports and progress reports may be automatically generated at termination of a test or at regular intervals, and can be accessed by users on the company network



  •  Cabinet Size. : 900 X 2200 X 4000 Approx.
  • Rollers : 150 Dia X 6000 Mtr Approx.
  • Blasting Unit. : 2 Nos 15” Ø X 2½” , 10 Hp motor.
  • Dust Collector Motor. : 7.5 Hp, 12” WG, 1300 CFM.
  • Bucket elevator. : 1 Hp, geared motor direct drive.
  • Roller Drive. : 1 Hp. Geared motor with bevel gears.
  • Loading of cylinder. : Manually
  • Unloading. : Manually

Shot Blasting Machine is an operation, which enhance the blast cleaning of cylinders for surface treatment. Rust removing and for painting.

The machine comprises of :

  •  Main body.
  • Seamless pipe rollers 2 nos,
  • Screw conveyor.
  • bucket elevator.
  • shot separator.
  • shot storage hopper.
  • shot control valve.
  • blasting unit.
  • dust collector.
  • interconnecting ducting
  • electrical control panel.

The main blasting chamber is fabricated out of 8 mm thick MS plate and necessary structural supports are provided to give it a adequate strength. The inside of the chamber is lined with abrasive resistance Mn. Steel lining 8 mm thick which protect the body plates from wear. The chamber is connected to dust collector. A grill is also provided at the bottom of chamber which prevents any large particles or jobs falling on to screw conveyor.
This is fitted at the bottom of the blasting chamber to carry the shots and fed to the bucket elevator. It is made out from 6 mm thick MS plate with proper helix. One edge of the screw conveyor flights are hard face to avoid fast wearing. The screw conveyor end shaft both are fitted in self aligned bearings which are mounted outside of the body.
The bucket elevator is fitted on the main body to lift the shots from bottom and fed to shot storage hopper. Crown pulley is mounted on the top of bucket elevator and other pulley to bottom to drive the belt assembly with buckets. Tension screws are provided to give tension to belt. Bucket elevator belt is driven through bonfingly Italy make geared motor with chain and sprocket.
The abrasive separator shall consist of wind shifting arrangement working on the principals of dynamic deflection of grains. The bucket elevator shall discharge shots, dust and sand into the wind shifting arrangement through a screw conveyor, which removes large size particles. The material shall be allowed to fall by gravity. The shots shall be arranged to fall in several cascades so as to increase the contact through at least 2 baffles. The arrangement shall insure a full length even thickness curtain of abrasive presented to the Air washing flow and even thickness curtain of abrasive curtain. This shell is connected to the dust extraction system to ensure collection of thoroughly cleaned shots into storage hopper. The arrangement shall be provided to prevent small abrasive from being carried out into dust collector.
The sound aerator valves are provided at the top of the turbine unit with feed spout and feed funnel to control the flow rate of shots and cut the shot supply when the impellers are stopped. These valves are to be operated by leavers manually or pneumatically.
The shot blasting turbines are the main part of the machine, which impinges shots on the components generally at right angle on the areas to be blast cleaned. There is one unit fitted on the top of main body. Which is the center line with the tables. It consists of a bare wheel, which is hardened and dynamically balanced. It is mounted on a shaft, which rotates in a bearing housing with taper roller bearings. The bare wheel assembly is enclosed in a fabricated housing with wear resistance Mn. Steel liners. Of shot is adjustable In 360 degree with the help of control cage. The complete list of liners and other part is illustrated in the enclosed drawing .
The efficiency of the blast cleaning on the proper control of dust in the main chamber and steel shot. If not controlled they may prove even health hazardous. Hence an efficient dust collector is always provide with machine. The dust collector is made of steel properly folded so that it can be easily disassembled. A plate fitted with 48 tube is fitted inside the body for filling of dust collector bags. the other end of the bags is hooked to the special hooks made out of steel bar. The hooks can swing in either direction by shaking mechanism. This is useful to shake out the dust from bags. A centrifugal balanced blower is mounted beside of the dust collector body. It sucks the Air from dust collector through bags. The dust sticks to the bags and clean Air is discharged. It is very essential to shake the bags to avoid clogging after every 8 hrs of working. Also check the condition of the filter bags every month replace the worn bags.
Interconnecting ducting between machine and dust collector is provided. Through this dust is sucked from shot separator and machine body. It has got a baffled adjustment to control the suction. Rubber sheet gaskets properly seal the joints of the ducting.


The electrical control panel is equipped with contactors, overload relays and MCB for each drive motor. Interlocking is provided to maintain sequence of operation and safety. Control panel is made suitable for 440 V, 50 cycle. All electrical parts used L & T make, Telemechanic or Siemens make.



All cylinders are subjected to hydrostatic test to check leaks if any, this is carried out at test pressure conditions and the pressure is applied for 30 seconds to check any pressure drop or leaks from body and weld joints
Every cylinder produced in a manufacturing location should undergo hydrostatic test. In this test, cylinders are subjected to hydrostatic test pressure of 25 kgf /cm2 and retain the pressure up to 30 seconds to check any pressure drop. Once the cylinder surface is dried, they are checked for leaks and pressure drop. If there is any pressure drop or any visible external leaks on cylinder body or on welds, the cylinder is disqualified for usage

Test Parameters : ( IS 3196-1: 2006 )
• Max Test pressure : 25 Bar
• No of test cylinders : 06 Nos ( Can be offered for 8 Nos & 10 Nos also )
• Test Temperature : Ambient
• Max cyl size :
• Min cyl size :
• Holding Time : 30 Sec
• Type of test : Hydro Proof Test

Main Equipment Consists of :
• Test Rig for Mounting of cylinders
• Tilting and clamping system
• Pressurizing Unit
• Water Recirculation System
• Local control Unit with PLC / HMI and electrical control panel
Ancillary Equipment / Items required :
• Low Pressure Air compressor for air
Display and Records :
• Proof Water Test Pressure
• Holding Time
• Pressure Drop, if any
• Test Medium Used
• Pressure v/s time graph ( in Scada Machines only )

Test setup for hydrostatic proof testing consists of a Cylinder mounting arrangement to test six to ten cylinders at a time and a pressurizing unit to provide required hydro test pressure . A local control panel is provided to display the status and test data . Local control panel with integral PLC and HMI system for local operation.

Cylinder Installation :
For ease in loading of cylinder, the frame is tilted by push button operation. After loading of cylinder and air release tubes , the cylinders are made vertical by push button operation. After reaching in to vertical orientation , cylinders are clamped by push buttons

Prefilling and Air evacuation system :

Pumping system for quick filling
Solenoid valves for air evacuation
Pressurizing Unit
A pressurizing unit is used to build up test pressure at the initialization of each test, and then to provide cylinder with pressurized water as required following minor leaks and expansion of test specimen.
The pressurizing unit consists of an electrically driven high pressure pump, pressure regulating system, hoses, sensors, and ancillary safety equipment.
Also supplied with the pressure testing system:
• Inlet water filter
• High pressure hoses
• Stainless steel Piping
• valves
• Electric control panel

Water Recirculation System :

• Auto injection of air to push the water to tank quickly
• Recirculation valve arrangement

Local Control Unit :
A local control unit will monitor the actual pressure till the cylinder is under pressure , display and report readings to the central control unit / HMI
The local specimen control unit consists of an electric panel comprising a PLC and HMI and signal conditioning electronics.
Also supplied as part of the local control unit:
• Digital display of pressure , time and status of test of each individual cylinder
• Outlets for additional calibration pressure transducer

Pneumatic leakage test :

Once service valve is fitted on LPG Cylinder every cylinder has to undergo pneumatic leak test. Under this test, pneumatic pressure of 1180 kPa is applied to cylinder to verify any leaks from cylinder body or weld leaks

Universal Testing Machine

Acceptance tests : IS 3196-3

Verification of metal properties like yield strength, tensile strength and percentage elongation of cylinder parent metal.

Verification of weld tensile strength of cylinder weld joints

Acceptance Test :
For every batch of 203 cylinders or less produced in a manufacturing location, one cylinder must undergo the acceptance test.

TS : 350- 450 Mpa
YS : 240 Mpa
PE : 25 %
Universal Testing Machine :

• Longitudinal Tensile Strength (LTS)
• Longitudinal Yield Strength (LYS)
• Longitudinal Percentage Elongation (LPE)
• Circumferential Tensile Strength (CTS),
• Circumferential Yield Strength (CYS)
• Circumferential Percentage Elongation (CPE)

Water capacity test :
In a water capacity test, cylinder water capacity is measured and checked whether they are within acceptable limits are not. Domestic LPG Cylinders in India are of 33.3 liter water capacity and its acceptable limit is within 33.30 liters to 33.95 liters as per Indian standard IS 3196 part 1


Radiographic examination :

Radiographic examination is intended to check weld quality and the weld defects in a cylinder during manufacturing process the examination is conducted on weld overlap to check weld defects