Roth DWT Installation Manual
16
Lubricating & Hydraulic Oil Storage and Dispensing
Emergency Venting
Emergency venting allows the expanding interior atmosphere of the tank to escape in
the event that the tank is exposed to external fire. Emergency vents are designed to
open at a pressure slightly above the opening pressure of normal vents.
The Roth DWT can be equipped with emergency vents for the primary tank. Sizing
of emergency vents is a function of the calculating the wetted surface area of the tank
and associated vent flow capacity requirements per NFPA 30. Please contact Roth
Industries Technical Department for assistance in sizing emergency vent equipment.
Interstitial emergency venting
Codes and ordinances may require emergency venting be applied to the interstitial
volume (space between the inner tank and the outer tank) in tanks with double wall
construction. The Roth DWT is constructed as a closed diked double wall tank with a
non-sealed interstitial, not designed for or capable of retaining pressure. Therefore,
there is no requirement or facility to install an emergency vent on the interstitial.
Testing and Inspection
1. As mentioned in Section 1, the inner and outer tanks of the Roth EcoDWT plus 3 are
pressure tested at the factory to UL specifications (4.35 psi inner and 0.25 - 0.3 psi outer).
Further pressure testing is not necessary and can result in damage to the tanks if attempted.
2. If pressure testing of the piping is required by local codes, all affected piping should be
disconnected from the tank and one end sealed prior to performing testing. Pressurization
of the piping should be no more than 0.5 psi (3.5 kPa) using a leak detection solution on the
fittings
3.
A hydrostatic test consisting of a thorough inspection of all connections during the first filling
should be conducted.
4.
Leaks found during these tests are generally from misaligned piping and loose fittings, or, on
rare occasions, from defective fittings. Once the problem has been identified and corrected,
review all aspects of the installation.
Example of an emergency vent, image courtesy of Morrison Bros. Co.
