Tech Tidbits, vol. 5 - PVC Piping and Electrostatic

Discharge in Hazardous or Classified Areas

On assessments performed in the last year, WEST has found many vessels have improper use of PVC

piping in a classified or hazardous area. PVC presents an explosion hazard because it is non-

conductive and susceptible to surface electrostatic buildup capable of igniting an atmosphere

containing explosive gas or liquid mixtures. These installations were mostly on third party equipment,

such as mud cleaning equipment. In some instances, the use of PVC was found as a permanent fixture

of the rig's mechanical installation. This material has been found in drains, vents, waterlines, mud

vacuum suctions, and chemical injection lines. Each of these installations has a distinct and dangerous

effect on vessel safety.

PVC piping used to transfer mud pit vapors to the main exhaust header.