Nace High Voltage Holiday Testing

They are effective for coating thicknesses of 500.

Nace high voltage holiday testing. Low voltage holiday detection also known as the wet sponge technique is used to test relatively thinly coated substrates. For example nace rp0274 guides the use of high voltage electrical inspection for pipeline coatings and nace rp0490 is the holiday detection of fusion bonded epoxy pipeline coatings from 10 to 30 mils. When a holiday is encountered current flows from the electrode into the substrate. The current returns to the detector through the ground earth wire completing the circuit and triggering audible and visible alarms.

Types of holiday testing devices. This standard is intended for reference in coating specifications or other documents and may be used by specifiers applicators and coating inspectors if a specification requires holiday detection on conductive substrates. Nace standards rp0188 hd1990 sg discontinuity holiday testing of protective coatings hd1990. 1 3 to prevent damage to a coating film when using high voltage test instrumentation total film thickness and dielectric strength in a coating system shall be considered in selecting the appropriate voltage for.

Nace tm0384 holiday detection of internal tubular coatings of less than 330 μm 13 mils dry film thickness. 4 4 coatings that are applied at a thickness of less than 0 5 mm 20 mil may be susceptible to damage if tested with high voltage spark testing equipment. Low voltage holiday detectors. Low voltage holiday testers are used for coatings up to 20 mils dft.

There are several industry standards regarding holiday testing including astm d 4787 d 5162 and nace rpo 188 88. These units are used to test thick film coatings such as those used by raven applicators. High voltage testers produce up to 40 000 volts of pulsed dc current. High voltage spark test equipment is generally used for determining the existences of discontinuities in coating films having a total thickness of greater than 0 5 mm 20 mil.

Low voltage wet sponge testers and high voltage spark testers. A high voltage holiday test is performed by moving a charged electrode over the coated surface. Sp0188 2006 formerly rp0188 discontinuity holiday testing of new protective coatings on conductive substrates available for download provides a procedure for electrical detection of minute discontinuities in coating systems that are liquid applied to conductive substrates other than pipelines. Types of test equipment.

Low voltage and high voltage holiday detectors. Available for download. There are other standards you might refer to for holiday testing besides nace sp0188.