monoblock gps-24-01.pdf

Oil States Industries, HydroTechDivision

1 Revision 28-July-98 GRD ODT LAD0 Issue for Use 01-May-97 GRD ODT LADA Issue for Review and Comment 22-Apr-98 JEG JEG JEG

Rev Origination ( 0 ) Revision ( D ) Date Prepared Reviewed Approved

GPS-24-01General Product Specification for

Pipe Insulating Joint (PIJ)


Pipe Insulating JointGSP-24-01

Date: 28-July-98Rev: 1Page 2 of 5

General Product Specification, GPS-24-01, defines the specifications for HydroTech systemsstandard Pipe Insulating Joints. Pipe Insulating Joints with alternate requirements can be designedand manufactured but are outside the scope of this document, although this Specification may bereferenced in part.

1. GENERAL DESCRIPTION

A Pipe Insulating Joint (PIJ), illustrated in Figure 1, is a high resistance monolithic or monoblockfitting used to electrically isolate sections of a pipeline. The primary purpose of electrical isolation isto improve the effectiveness of cathodic protection systems and to reduce ground loop currents.Unlike insulating flanges or flange kits which are usually field assembled and tested, the PIJ isfactory assembled, electrical tested at five different stages of manufacturing and hydrostaticallytested. The PIJ is provided with Extension Nipples, matching the pipeline wall and grade, ofsufficient length to eliminate any possibility of thermal damage to the Fitting during field welding.

The monolithic design of the PIJ results in a pipe fitting having high cyclic bending strengthintegrity. This aspect is particularly important for offshore pipeline riser applications where cyclicloading is common. The integrity of the PIJ is further enhanced by the use of high temperaturefluorocarbon (Viton) seals and insulation of high pressure glass filled structural epoxy laminate.The clean monolithic profile will not trap moisture and reduces the possibility of crevice corrosion.This is an additional advantage of the monolithic design over conventional insulating flanges inoffshore pipeline applications.

HydroTech Systems maintains an inventory of Pipe Insulating Joints up to 900 ANSI ratings innominal sizes from 4 inch to 8 inch with schedule 80 bores and API 5L Grade B pipe ExtensionNipples. Pipe Insulating Joints can be designed and manufactured for any size pipeline.

2. DESIGN REQUIREMENTS

Pipe Insulating Joints designed to this General Product Specification are in accordance with theASME Pressure Vessel Code, Section VIII, Division 1, unless another recognized code is specifiedby the purchaser. A PIJ is designed to be at least as strong as a comparable rated pipeline whensubjected to external loads.

The electrical resistance, leakage current and breakdown voltage is a function of the insulatingmaterial, insulator thickness and capacitance. The electrical resistance of the PIJ is at least 40megohms with 1000 VDC applied potential and the maximum leakage current, with 2500 VAC (60Hz) applied potential, is 5 mA. The dielectric strength (breakdown voltage) of the PIJ is designedto be in excess of 20,000 volts.




3. MATERIALS AND COATINGS

Standard materials for Pipe Insulating Joints are tabulated below along with the appropriateHydroTech Material Specification (HMS). The appropriate standard material for a particular PIJEnd Flange, Retainer Flange and Hub is based on the matching pipeline material grade. The PIJAssembly is externally protected by three coats of high build epoxy per HydroTech CoatingSpecification, HCS-4. Bare internal surfaces and butt-weld preparations are coated with atemporary rust preventive per HCS-6.

Component Material

End Flange

ASTM A105 (HMS-1) for matching pipegrades up to and including API 5L-X42ASTM A694 Gr F46 or Gr F52 (HMS-16,CL 1 or 2) for matching pipe grades aboveAPI 5L-X42

Hub


Retainer Flange


wExtension Nipples API 5L-Grade to match pipelineInsulator Rings Glass filled epoxy laminate, NEMA Gr G10

Insulation Epoxy Aluminum oxide filled resinO-Ring Seals Molded Viton (HMS-14)

wWhen the pipeline has an uncommon wall thickness, grade or special material requirements, pipefor the Extension Nipples intended to match the pipeline, must be supplied by the purchaser.

4. QUALITY ASSURANCE

The part and heat number of each PIJ End Flange, Hub, Retainer Flange and Extension Nippleare steel stamped. Each Assembly also has a unique serial number stamped on the outsidediameter of the Retainer Flange for complete material traceability. Dimensional inspectionreports and material test reports for each component are maintained on file.

The welds to the Extension Nipples are 100% radiographically examined per ASME SectionVIII, Division 1, Part UW-51 and the End Flange-to-Retainer Flange weld is ultrasonically




examined per ASME Section VIII, Division 1, Appendix 12.

In accordance with HydroTech Quality Assurance Procedure, HQA-496, the insulatingcharacteristics of each PIJ is tested before welding, after welding and after injecting with epoxy.Each PIJ is then hydrostatically tested to 1.5 times the design pressure for a minimum of 1 hourand the insulating characteristics are tested twice more per HydroTech Quality AssuranceProcedure, HQA-489. The final two tests of the insulating characteristics are conducted afterhydrostatically testing and finally after coating.

Upon request, up to two sets of Quality Assurance documentation will be provided for all PipeInsulating Joints. The documentation shall consist of the following:

Certificate of Conformance Material Test Reports for pressure containing components NDE Reports for radiography of welds NDE Report for ultrasonic examination of weld PIJ Epoxy Injection Procedure, HQA-496 Acceptance Test Procedure, HQA-489, and Test Chart Heat Sketch for each pressure containing component identifying:

Part number H number (traceable to vendor heat number) Serial number HydroTech purchase order number HydroTech sales order number

5. ORDERING INFORMATION

The following minimum information must be specified on any request for quotation or purchaseorder for a PIJ intended to meet this General Product Specification, GPS-24-01.

Nominal pipe size Pipe wall thickness or bore Pipe grade Design rating

Revision Record

Revision # Date Page Revision Detail

1 July 1998 Page 2, Section 2,Second Paragraph

Replace 5000 with 2500

monoblock gps-24-01.pdf

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