Permeability

Penetrability.

PFA

Pulverized Fuel Ash; a fine powder residue after burning carbon based products. Especially from electricity generating stations.

pH

A measure of the acidity or alkalinity of a solution. A value of seven is neutral; low numbers.

Physical Pipe Inspection

The crawling or walking through manually accessible pipe lines. The logs for physical pipe inspection record information of the kind detailed under TELEVISION INSPECTION. Manual inspection is only undertaken when field conditions permit this to be done safely. Precautions are necessary.

Piercing Tool

See Earth PiercingThe use of a tool that comprises a percussive hammer within a suitable, generally torpedo-shaped casing. The hammer may be pneumatic or hydraulic. The term is usually associated with nonsteered devices..