Weld Pad Liquid Level Gauge
A weld pad type liquid level gauge is an instrument which is designed to be used where it is not possible or practical to install a conventional reflex / transparent gauge and where there may be solids present in the liquid that would interfere with the operation of a traditional instrument.
This type of gauge is designed so that it can be continuously welded via the chamber directly to the vessel upon which it will be measuring. The base which is welded can be either flat or radius bottomed to suit the vessel configuration and the glass is almost always reflex type as it is not possible to provide illumination from inside the tank from where the gauge is installed.
It is common that weld pad level gauges are used in non critical applications and in most cases they are supplied without any form of isolation. It is possible however to supply weld pad gauges with a needle valve located directly on the chamber at the top / bottom which will offer a form of isolation from the process.
Due to this type of instrument being welded after delivery the unit is supplied loosely assembled, the recipient will then line up the gauge dismantle the gauge and weld the instrument body to the empty vessel.
Weld pad gauges are not pressure tested as an individual unit as the method of construction / assembly does not allow for this. The instrument should always be pressure tested by the purchaser as part of the complete system after installation.