LPG Storage Tanks

Mellcon can supply multiple LPG Liquefied Petroleum tanks LPG Mounded Bullets & systems in a range of sizes to suit the requirements of the customer on Turnkey Basis duly approved by the CCOE chief Controller of explosives as per SMPV Rules. (Pdf)

The two main forms of LPG are commercial butane and commercial propane. LPG may be liquefied by moderately increasing the pressure or by reducing the temperature. Refrigerated storage is used by gas suppliers to store large volumes of LPG. The main form of LPG storage is in special tanks known as 'pressure tanks'. Commonly these pressure tanks are termed 'bulk tanks' or LPG Bullets. because LPG has a high coefficient of expansion in its liquid phase, the tanks are never completely filled with liquid (tanks are filled to approximately 85% of their water capacity), the remaining space being taken up with vapor (often referred to as the vapor space) to facilitate expansion without allowing the liquid to become 100% full (often known as hydraulically full).

As LPG gas (vapor) is drawn from the tank, the vapour pressure in the tank falls and the liquid boils, producing more vapour and restoring the pressure.to maintain boiling, the liquid absorbs heat from itself, from the metal alls of the tank in contact with the liquid (known as the wetted surface area) and from the air surrounding the tank. The available gas 'off take', therefore, is dependent upon the surface area of the tank, the quantity of liquid within the tank and the temperature. The low temperature of the liquid (often indicating excess Off take) may be indicated as 'sweating' (where the water vapour in air condenses on the wetted surface area of the tank) and if the off take is large enough 'frosting' (where the condensed water vapour freezes) on the walls of the tank.



When the liquid temperature rises, for instance in summer, the vapor pressure increases, when the liquid temperature drops, the vapor pressure drops. Under normal Indian conditions the pressure range will be between 2-9 bar.

These are designed as per the recommendations in IS-2825 / ASME Sec Vlll DlV - 1 codes and the material of construction are SA-516 / IS-2062/ IS-2002/SS-304 or as per the specific requirement of the customer. Steel used for the Tank and its fittings meets the Low Temperature Carbon Steel criteria and is tested thoroughly before fabrication. During Fabrication stringent quality norms are followed. Each tank undergoes various NDT & other inspection stages . We carry out tests like Dye Penetration Test, Radiographic Examination and the Hydro test.before despatch.

The vessels are stage wise inspected by our Inspection engineers / Third party Inspectors as per the recommendations of the relevant code and the Chief controller of explosives norms. All welding are performed by qualified welders only. Finally it is hydro tested and de-hydrated with dry nitrogen. MELLCON also offers these tanks under any third party inspection according to customers specific requirement.

These storage tanks are equipped with all standard instruments and controls like Rochestr gauge, excess flow check valves, safety valves, Pr. gauges, LPG Transfer compressor, Valves, Piping, Drains, Pr.Regulators, Water sprinkling system , gas leak detection system & a suitable Control panel. Optionally a Digital weighing scale can also be supplied as an integral part.

Most LPG storage tanks in standby-plant service are steel, non-refrigerated pressure vessels. Tanks are available in many sizes for both aboveground and underground service. New propane tanks are built to ASME standards and are designed for at least 250 psig working pressure. Common tank sizes and approximate dimensions are shown in the chart below. Larger industrial and commercial applications generally use 18,000 gallon and larger tanks.

 » Technical Specification
Standard design As per ASME sec VIII Div 1 Pressure Vessel Code
Pressure design 18.0  bar
Design Temperature(atm) range -20 / +50 °C
Hydraulic Test Pressure 25.0 bar
Joints efficiency 0.85
Radiographs 100 %
Manhole 1
Flanging  # ASA 300
Gates 8
Thickness 6 mm to 50 mm
Diameter 600 mm to 3000 mm
Length Up to 18 Meters Long
Weight 3000 To 80000 Kgs
  » Typical Sizes Available
2. 4., &  6  Tons
8 & 10, Tons
12 & 15 Tons
18 & 20 Tons
26 & 30 Ton
36 & 40 Tons
We undertake Range of Turnkey Projects for LPG, propane, ammonia, CO2 , Nitrous Oxide , Ethylene oxide and all other liquefiable gases

» Accessories » Materials of Construction » Design Codes Followed
» LPG Transfer Pump / Compressor
» LPG Vaporizers
» Pressure Reducing station
» Emergency shut off valve
» Gas Leak Detection System
» Water Sprinkler System
» Rochester Gage / Roto gage
» Excess Flow check valve 		» SA 515 / 516 Grade 60 / 65 / 70
» SA 537 Class I / Equivalent.
» SS 304 / 304 L
» SS 316 / SS 316 L
» SA 387 P 11 Class II 		» IS -2825 Class 1 With latest Addenda
» PD - 5500 – 2003 Edition
» TEMA
» ASME Sec.VIII Div 1& 2 – 2001 + latest addenda
» IBR Code No. ISOR / 831-1968 / IBR
» API 650
» IS 803
SAFETY FITTINGS FOR THE TANKS
There are various safety fittings we supply for the storage tank they are grouped as under
» Pressure Relief Valves
• Single Port
• Multi Port
» Excess Flow heck Valves
• Threaded Type
• Sandwich Type		 » Level Gauges
• Fixed Liquid Level Gauge
• Roto-Gauge
• Simple Magnetic Level Gauge
• Rochester Gauge
• Magnetorestrictive Type
• Servo Level Gauge
• Reflux Type
• DP Type
» Alarms
 • High and Low level Alarms
• High Pressure Alarm 		»Temperature and Pressure
• Pressure Gauge and Transmitter
• Temperature Gauges and Transmitter
» Remote Operated Valves
• Pneumatically activate, with or without manual over ride
• Solenoid Valves
• Motorized Control Valves