GB/T 38097-2019 Urban heating - Prefabricated directly buried insulating pipes and fittings with polyurethane (PUR) foamed-plastics and glass fiber reinforced plastics protect layers
1 Scope
This standard specifies the terms and definitions, construction, requirements, test methods, inspection rules, marking, transportation and storage of prefabricated directly buried insulating pipes and fittings with polyurethane (PUR) foamed-plastics and glass fiber reinforced plastics protect layers.
This standard is applicable to the prefabricated directly buried insulating pipes and fittings whose conveying medium temperature (long-term operating temperature) is not higher than 120 °C and accidental peak temperature is not higher than 140 °C.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 3091 Welded steel pipes for low pressure liquid delivery
GB/T 8163 Seamless steel tubes for liquid service
GB/T 8237 Liquid unsaturated polyester resin for fiber reinforced plastics
GB/T 8923.1-2011 Preparation of steel substrates before application of paints and related products - Visual assessment of surface cleanliness - Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous
GB/T 9711 Petroleum and natural gas industries - Steel pipe for pipeline transportation systems
GB/T 12459 Steel buttwelding pipe fittings - Types and parameter
GB/T 13401 Steel buttwelding pipe fittings - Technical specification
GB/T 18369 Glass fiber roving
GB/T 18370 Glass fibre woven roving
GB/T 29046-2012 Test methods of technical specification for pre-insulated directly buried district heating pipes
GB/T 29047-2012 Prefabricated directly buried insulating pipes and fittings with polyurethane foamed-plastics and high density polyethylene casing pipes
GB 50236 Code for construction of field equipment, industrial pipe welding engineering
CJJ/T 254 Technical specification for leakage surveillance system of directly buried heating pipe
NB/T 47013.2 Nondestructive testing of pressure equipment - Part 2: Radiographic testing
NB/T 47013.3 Nondestructive testing of pressure equipment - Part 3: Ultrasonic testing
NB/T 47014 Welding procedure qualification for pressure equipment
SY/T 5257 Steel bends for oil and gas transmission
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 29047-2012 and the following apply.
3.1
long term mechanical properties of casing
long-term aging resistance of the casing material assessed based on the time of brittle failure of the material under the accelerated test condition at certain stress, temperature and medium environment
3.2
bend angle deviation
difference between the nominal bend angle of elbow or bend and the measured bend angle of product
4 Construction
4.1 Prefabricated directly buried insulating pipes with polyurethane (PUR) foamed-plastics and glass fiber reinforced plastics protect layers (hereinafter referred to as "insulating pipes") or insulating fittings shall be of a trinity structure in which working steel pipes or steel pipe fittings, insulating layers and protect layers are closely fitted, and trestles and alarm lines can be set in the insulating layers.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Construction
5 Requirements
5.1 Working steel pipe
5.2 Steel pipe fittings
5.3 Protect layer
5.4 Insulating layer
5.5 Insulating pipe
5.6 Insulating pipe fittings
5.7 Insulating joint
6 Test methods
7 Inspection rules
7.1 End-of-manufacturing inspection
7.2 Type inspection
8 Marking, transportation and storage
8.1 Marking
8.2 Transportation
8.3 Storage
Annex A (Normative) Manufacture of insulating joint
Annex B (Normative) Test method for Barcol hardness of protect layer
Bibliography
