φ50 Welded Type Sonic Logging Pipe (50mm Sleeve Welded CSL Pipe)

The φ50 (50mm OD) Welded Type CSL Pipe is a universally specified and highly economical solution for standard Cross-hole Sonic Logging (CSL). Utilizing an enlarged steel sleeve coupling to join two pipe sections, this pipe is permanently sealed on-site via classic fillet welding. It is the premier choice for large-scale, cost-sensitive foundation projects where maximum joint integrity is demanded without the premium costs associated with threaded or hydraulic fittings.

Key Features & Advantages

Continuous Steel Fusion: Once welded on-site, the sleeve joint provides a permanent, continuous steel connection that completely eliminates the risk of cement slurry ingress.

Highly Cost-Efficient: Free from precision-machined threads or complex hydraulic flaring, the φ50 configuration offers the most competitive pricing for high-volume procurement.

Standard Probe Compatibility: Perfectly sized for standard 25mm CSL probes, providing a smooth, consistent internal diameter through the joint channel.

Universal Engineering Acceptance: Complies with major international geotechnical testing standards, making it highly versatile for structural pile inspection.

Technical Specifications

The φ50 sleeve welded sonic logging pipe is manufactured to strict dimensional standards:

Parameter	Specification Details
Outer Diameter (OD)	50 mm
Wall Thickness (WT)	1.0 mm to 3.5 mm
Material Grade	High-Quality Carbon Steel (Q195 / Q235 / ASTM A53)
Connection Method	Sleeve Overlap + Fillet Welding
Sleeve Length	80 mm to 150 mm (Customizable)
Surface Treatment	Bare (uncoated) / Black Varnished

Quality Control & Precision Standards

Burr-Free Pipe Ends

Both ends of our φ50 steel pipes are thoroughly deburred and smoothed. This prevents snagging of the ultrasonic probes and allows the field welder to slide the pipe into the sleeve coupling without friction.

Precise Sleeve Alignment

The inner diameter of the enlarged steel sleeve is strictly controlled during factory expansion. This guarantees a snug fit over the raw pipe end, simplifying alignment on the rebar cage platform and saving welding time.

Installation Instructions

Slide: Slide the enlarged steel sleeve coupling onto one end of the first φ50 pipe section.

Align: Insert the plain end of the second φ50 pipe into the other end of the sleeve until they butt together in the middle.

Weld: Execute a full-circle fillet weld at both ends of the sleeve coupling to ensure a watertight, structural joint.

Frequently Asked Questions (FAQ)

Q: What is a φ50 Weld-on sonic logging pipe, and why do standard projects specify it?

A: A φ50 Weld-on sonic logging pipe is designed for permanent joints connected via on-site sleeve welding. Standard civil projects specify weld-on tubes because a properly executed steel-to-steel weld joint delivers identical tensile strength and structural rigidity as the parent pipe body. It eliminates any reliance on rubber seals or mechanical threads, providing maximum structural reliability at an economical price point.

Q: What end finishes do you provide to facilitate high-efficiency on-site welding for φ50 pipes?

A: To ensure fast and precise alignment on the rebar cage platform, we offer Enlarged Socket Sleeves (bell ends) pre-welded to the pipe end. The socket-sleeve option allows the next pipe to slide easily into the pre-expanded end of the lower pipe, maintaining axial alignment and creating a natural lap joint that your site welders can fuse quickly.

Q: What steel grades do you use for φ50 welded tubes, and how do you guarantee weldability?

A: We utilize premium low-carbon steel (such as Q235B or ASTM A53 Grade A/B) specifically selected for its low carbon equivalent (CEV). This chemistry ensures outstanding weldability under standard field conditions, minimizing the risk of weld cracking or embrittlement during rapid cooling. All properties are certified via our EN 10204 3.1 Mill Test Certificate (MTC).

Q: Does the heat of welding cause internal slag that could block the φ50 ultrasonic probe?

A: No. For our sleeve-welded configurations, the fillet weld is executed entirely on the outside lip of the expanded sleeve. The inner channel remains perfectly smooth and uncompromised by heat or slag, guaranteeing an unobstructed, straight path for the CSL ultrasonic probes to lower smoothly.

Q: Do you provide matching steel bottom caps and temporary top plugs for φ50 welded pipes?

A: Yes. We provide heavy-duty, pre-welded watertight steel bottom plates to seal the base of the first tube string. For the top of the tubes, we supply temporary plastic or steel caps to prevent concrete splashes, mud, or rainwater from introducing debris into the testing channel during cage installation.