The relevant provisions in the national standard for steel pipe fittings “GB/T13401-2017 Technical Specifications for Steel Butt Welded Pipe Fittings”:
7.3 Non-destructive testing
7.3.1 Tees, crosses, press-formed reducers, and pipe caps formed by the direct cutting of bars of all material categories should be non-destructively inspected piece by piece; among them, carbon steel, alloy steel, and low-temperature steel categories Magnetic particle testing shall be carried out according to NB/T47013.4 or relevant specifications. Penetration testing for stainless steel shall be carried out according to NB/T47013.5 or relevant specifications. Level I is qualified.
7.3.2 In addition to the varieties mentioned in 7.3.1, other pipe fittings of the alloy steel category (including pipe fittings of material grade LF450K3 and LF680K4 in the low-temperature steel category) shall be magnetic particle tested piece by piece according to NB/T47013.4 or relevant specifications, I grade is qualified.
7.3.3 In addition to the provisions of 7.3.5, when the welds of welded steel pipe fittings are completed by the steel pipe fittings manufacturer, the full length of the welds of the welded steel pipe fittings shall be radiographed by NB/T47013.2 or relevant specifications. Level II is qualified (excluding flanged pup joints manufactured according to 5.6).
7.3.4 In addition to the provisions of 7.3.5, for welded steel pipe fittings made of straight seam welded pipes, if the welds have been 100% radiographic tested by the welded pipe manufacturer and qualified for Level II, the welds of the steel pipe fittings may no longer be Radiographic testing, unless otherwise required. If the welded seam of the welded pipe has not been 100% radiographic tested by the welded pipe manufacturer, the full length of the welded seam of the welded steel pipe fittings should be radiographed according to NB/T47013.2 or relevant specifications. Level II is qualified.
7.3.5 For welded steel pipe fittings whose usage conditions do not require radiographic inspection of weld seams, the welds may not require radiographic inspection after negotiation between the supplier and the buyer, but a suffix should be added to the material grade of the steel pipe fittings in the delivery document and physical mark. Letters NX, such as CF370NX.
7.3.6 In addition to the above provisions, non-destructive testing can be carried out according to the content negotiated between the supplier and the buyer; such as magnetic particle, penetrant, and ultrasonic testing as required separately.
Post time: Oct-16-2023