GENERAL MK SERIES HDD Pump

**Frame and Base: The Foundation of Stability**

The MK series frame is constructed from welded high-strength steel plates. Compared to traditional cast frames, this structure provides equivalent or higher strength while significantly optimizing weight, offering advantages for field deployment and transportation.

**Crankshaft and Gear Assembly: Precision Power Transmission**

* **Crankshaft Material and Manufacturing Process:** As the core rotating component of the power end, the MK series crankshaft is forged from high-quality alloy steel (42CrMo or 4140).

* **Gear Design and Standard:** The MK series employs a herringbone (double helical) gear drive.

* **Pinion Shaft:** The pinion shaft is also forged from high-strength alloy steel (42CrMo). Its shaft ends extend on both sides, allowing the drive pulley or sprocket to be installed on either side as required by field conditions, providing additional drive arrangement flexibility.

**Connecting Rods and Crossheads: Smooth Rotary-to-Reciprocating Conversion**

* **Connecting Rods:** We selected high-performance, fatigue-resistant aluminum alloy connecting rods for the MK series.

* **Crossheads and Guides:** The crosshead body is made from high-quality cast steel, while the guide plates, which are its key wear partners, are made from manganese bronze material.

**Bearings and Lubrication System: Ensuring Longevity**

* **Bearing Configuration:** The crankshaft, pinion shaft, and crosshead pins in the power end are equipped with top-tier heavy-duty roller bearings. These bearings are carefully selected and calculated to withstand the high radial and axial impact loads inherent to reciprocating pumps, forming a crucial guarantee for the reliability of the entire power end.

* **Lubrication System:** The MK series uses an efficient and reliable splash lubrication system, ensuring all moving parts like gears and bearings are constantly immersed in lubricating oil. Simultaneously, the power end housing is optimized for excellent heat dissipation, helping maintain the oil at its optimal operating temperature, thus ensuring lubrication effectiveness and extending component life.

**Fluid End – Precision and Durability at the Wear Frontier**

**Fluid Cylinder and Manifold: Pressure Containment System**

* **Fluid Cylinder Module Construction:** Our fluid cylinder modules are integrally forged from high-strength alloy steel (AISI 4135 or 35CrMo) and undergo strict quenching and tempering heat treatment, enabling them to reliably withstand working pressures up to 7,500 PSI. Compliance with API Spec 7K standards ensures their safety, reliability, and interchangeability with components from other brands.

* **Manifold:** The manifold is made from cast iron and treated with an electroless nickel plating. This dense nickel-phosphorus alloy coating is not only hard but also offers exceptional corrosion resistance, effectively protecting the manifold body from erosion by various chemical additives and scouring by solid particles in the drilling fluid, thereby extending its service life.

**Liner Technology: The First Line of Defense Against Wear**

* Structure and Process: This liner uses a dual-layer structure: an outer shell of high-strength forged steel provides powerful pressure resistance; an inner layer of high-chrome cast iron wear-resistant liner (typically with chromium content exceeding 27%) is formed through centrifugal casting. Centrifugal casting ensures a dense, defect-free structure and uniform hardness in the wear-resistant layer. Subsequently, the wear-resistant inner sleeve is press-fitted into the outer shell under high pressure, forming a strong metallurgical bond.

* Performance Characteristics: The hardness of the high-chrome inner sleeve can reach Rockwell Hardness HRC 58-69, offering extremely strong resistance to abrasive wear. It effectively resists scouring by hard particles like quartz sand and cuttings in the mud, with a service life exceeding 800 hours under standard conditions. This is the industry-standard configuration suitable for the vast majority of drilling applications, offering high cost-effectiveness.

* **Option 2: Zirconia Ceramic Liner**

* Structure and Process: Advanced powder metallurgy and sintering processes are used to create the inner sleeve from a proprietary formula zirconia ceramic matrix composite.

* Performance Characteristics: Zirconia ceramic liners represent the highest level of current liner technology. Their hardness is extremely high (HRC >90), far exceeding high-chrome alloy, while their fracture toughness is better than traditional alumina ceramics, demonstrating stronger impact resistance. More crucially, the surface of zirconia ceramic can be honed to a very high finish (4-8 RMS), creating a mirror-smooth working surface.

* Customer Value: This ultra-low friction surface significantly reduces the coefficient of friction against the piston, thereby greatly extending the service life of the piston rubber and reducing heat generated by friction, lessening the load on the cooling system. Its exceptional wear resistance allows for a service life reaching 2000 to 4000 hours or more, several times that of high-chrome liners. For drilling operations on costly offshore platforms or in remote areas, using zirconia ceramic liners can drastically reduce downtime for replacements and significantly lower the total lifecycle operating costs.

* **Piston Structure:** Our pistons feature a robust and durable two-piece design. The piston core is integrally forged from 42CrMo alloy steel, ensuring it does not deform or fracture under high pressure. The piston core is firmly bonded to the high-performance elastomer through an advanced vulcanization process.

* **Elastomer Options:**

* Bonded Polyurethane (PU): Designed specifically for oil-based muds and high-pressure conditions. Our dual-durometer polyurethane formula offers excellent resistance to chemical swelling and extrusion while ensuring sealing performance.

* Nitrile Rubber (NBR) / Hydrogenated Nitrile Rubber (HNBR): NBR is an ideal, cost-effective choice for water-based muds. HNBR provides superior high-temperature resistance and chemical resistance, suitable for more demanding conditions.

* **Piston Rod:** The piston rod is a key component for transmitting power, made from high tensile strength SAE 4140 alloy steel. After high-frequency quenching and precision grinding, the rod body undergoes hard chrome plating, forming an extremely smooth, hard, and corrosion-resistant surface layer. This chrome layer ensures the packing seals can slide smoothly on it, achieving reliable sealing and maximizing the service life of both the seals and the piston rod itself.

* **Valve Assembly:** We offer various valve assembly designs, including full-open and web-type, to adapt to muds of different viscosities and solid contents. Both valves and seats are forged from high-strength alloy steel and undergo integral heat treatment. Their design and dimensions strictly adhere to API 7K standards, ensuring interchangeability with other mainstream products in the industry. The sealing surface of the valve seat receives special hardening treatment to resist high-speed erosion by mud.

* **Seals and Packing:** The sealing integrity of the fluid end is crucial. We provide seals made from various materials to handle different fluid media and temperatures.

* Nitrile Rubber (NBR): Suitable for water-based muds and standard conditions.

* Hydrogenated Nitrile Rubber (HNBR): Suitable for high temperatures, oil-based muds, and conditions involving chemical additives.

* Polyurethane (PU): Offers the best wear resistance and anti-extrusion performance.

* Kevlar Reinforced Packing: In extremely high-pressure and abrasive environments, this high-performance packing provides the longest-lasting and most reliable seal.

To assist customers in selecting the most economical and efficient combination of wear parts based on specific working conditions, we provide the following selection matrix as a reference:

**Wear Parts Selection Matrix**

Through this advisory selection support, we aim to help customers build a wear system tailored to their specific application that offers the best cost-effectiveness, thereby translating our engineering advantages into tangible operational value for the customer.

**Performance Specifications Table**

The table below summarizes the core performance parameters of various models in the GENERAL MK series. Customers can quickly identify the most suitable pump model based on the flow rate and pressure range required for their project.

**Dimensions and Connection Data**

To facilitate equipment layout, foundation design, and piping connection for our customers, the general physical parameters for the MK series pumps are provided below.

* **Pump Body Dimensions:**

* Length x Width x Height: 32.64 in x 29.38 in x 14.25 in (829 mm x 746 mm x 362 mm)

* **Connection Ports:**

* Inlet Port: Available in either 2" NPT or 3" NPT depending on the model. Ports are located on both sides of the pump body for convenient piping connection.

* Discharge Port: 1" NPT.

* **Crankcase Oil Capacity:**

* 456.5 oz / 13.5 liters.

* **Max. Inlet Pressure:**

* 45 PSI (3.1 bar).

* **Max. Fluid Temperature:**

* 140°F (60°C).

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