VOT cylinders for LPG (Vapour – Off – Take)
VOT Cylinders are the normal conventional type of cylinders which you would find in your homes, restaurants and other small commercial establishments These type of cylinders were introduced in India after independence with a view to provide LPG for cooking in homes.
In these type of cylinders, the vapour is converted naturally inside the cylinder is discharged out through a VOT cylinder valve and used for usage applications.
The rate at which liquid LPG inside the cylinder is naturally converted into LPG vapour and discharged for usage is around 0.4 to 0.7 kg/hr.
These type of cylinders are often required in household kitchens, commercial kitchens, restaurants, canteens, small industries, etc in multiple quantities connected in series for higher off-take where there is a higher consumption rate of LPG.
The standard configurations and schematic views of a VOT cylinder bank according to the consumption pattern of the user is as below:
Schematic View of VOT Cylinder Installation for Commercial Kitchen
Advantages of VOT:
- Easy availability of Cylinders.
- Systems are commercially viable compared to LOT.
Disadvantages of VOT:
- Gas bank Installation consumes more space.
- Residual gas is present in the cylinder.
- Suitable only for low rate of consumption.
Limitations of VOT Installations:
Inadequate cylinder banks result in pressure drops in the VOT system throughout the year especially in peak hours or winter season. It is initially designed for the usage estimated and installed at the initial commencement of the project and subsequently more burners and equipment fired on LPG are added but the VOT cylinder bank remains the same.
There are occurrences of cylinders getting frozen with ice formation on the exterior of the cylinders, hot water buckets are used to increase the natural evaporation rate of LPG, which is a wrong & dangerous practice. Unnecessarily money and energy are spent to recover the residual LPG and increase the pressure output from VOT cylinders.
It is observed that the full cylinder bank is not pressed into service by the operators.Less number of cylinders are connected to the bank and fresh cylinders are connected to the same cylinder bank in cycles (regular intervals) to maintain the pressure in the system. Dedicated personnel are deployed for this purpose only.