HQ Water Swivel Crossover Sub DCDMA Standard Alloy Steel Reducing Adapter for Wireline Core Drilling

NQ Adapter sub faucet size-changing connector (variable coupling, conversion short section) is a key auxiliary tool commonly used in wireline core drilling operations. It is mainly used for connecting the water swivel of the drilling rig with HQ standard drill pipes， external pipe assemblies， and active drill rods， and is suitable for converting PQ large-diameter water swivel to HQ medium-diameter drilling tools for construction. It solves the problem of incompatible interface sizes of drilling tools and the inability to directly connect. The product is made of high-strength alloy steel through overall forging and quenching treatment. It is precisely machined using CNC to form DCMA standard threads， featuring high coaxiality， strong pressure-bearing capacity， and stable sealing performance. The inner hole has a smooth passage without throttling， ensuring the stable circulation of high-pressure mud without leakage or pressure loss. It is a core and frequently used conversion accessory for medium and deep-hole geological exploration， geothermal drilling， and geotechnical engineering investigation projects. 

Product core function
- Different diameter threaded connection: Enables quick connection of PQ large-diameter faucets to HQ standard drill pipes, without the need to replace the entire machine's faucet. It is compatible with the entire HQ series of single-layer and three-layer pipe drilling tools for construction.
- Universal reusability of equipment: One large-diameter drilling rig can freely switch between PQ and HQ multiple specifications for drilling modes, significantly increasing the utilization rate of the drilling rig and reducing the cost of repeated equipment purchases.
- Mainly suitable for deep holes: Compatible with kilometer-level deep-hole drilling conditions, covering both conventional exploration and shallow deep well construction of geothermal energy, with extremely strong versatility.

- Integrated Variable-Diameter Double-Thread Structure: The upper end is compatible with the PQ large-diameter faucet threads, while the lower end is the standard HQ drill pipe threads. The transition section is thickened for enhanced strength, with high torsional resistance. It can rotate at high speed without vibration or deformation.
- Integral Forging and Quenching Material: Utilizes high-quality alloy structural steel for integral forging and heat treatment quenching. It has excellent tensile, impact, and fatigue resistance, suitable for deep well, high-pressure, and heavy-load working conditions.
- DCDMA Precision Threads: Numerical control precision turning of standard threads, with full tooth profiles and uniform mating clearance. The connection is tight and disassembly is smooth. It is not prone to thread slippage, breakage, or jamming during long-term high-pressure operations.
- Full-Through Diameter Smooth Inner Hole: No stepped or reduced diameter design. The mud flow resistance is low, ensuring stable circulation of high flow and high pressure, meeting the requirements for slag removal in medium and deep hole drilling.
- Corrosion-Resistant Hardened Surface Treatment: Overall blackening anti-rust process, resistant to mud erosion, acid and alkali corrosion. It can be used stably in outdoor damp and harsh mining environment for a long time.

1. Multi-specification compatibility, significantly reducing equipment costs
No need to install a dedicated HQ faucet. By installing this reducer connector, the PQ drilling rig can directly carry out HQ medium-sized core sampling operations. This one machine can be used for multiple purposes, allowing for flexible adjustment of the drilling diameter, greatly reducing equipment idleness and investment costs.
2. High-pressure sealing and no leakage, stable drilling conditions
High precision of threaded connection, under high-pressure mud conditions, the seal is tight without water leakage, pressure loss, or pressure drop, ensuring stable cooling and slag discharge at the bottom of the hole, improving drilling efficiency and reducing construction faults.
3. High coaxiality and low vibration, protecting the entire drilling tools
Integrated precision processing, precise coaxiality, stable rotation, minimal oscillation, effectively reducing wear and damage to the water swivel， drill pipe， and threaded joints， extending the service life of the entire drilling tools.
4. Heavy-duty and high strength， suitable for medium and deep hole operations
Quenched alloy steel material has strong bearing capacity， anti-torsion and anti-fatigue properties， suitable for drilling in kilometers of medium and deep holes， conventional geothermal wells， and heavy-duty drilling in fractured formations， with durability far exceeding ordinary turned connectors.
5. Easy disassembly and assembly， efficient on-site switching
Standard universal threads， can be quickly disassembled and replaced in the field， no need to modify the drilling rig structure， quickly complete the switching between different diameters for drilling， improving the overall drilling progress.