Extension Rods

Parameter	Specification
Product Name	Mud Pump Extension Rod
Alternative Names	Pony Rod, Intermediate Rod
Product Category	Drilling Mud Pump Power-End Components
Equipment Type	Reciprocating Drilling Mud Pump
Material	Forged alloy steel, subject to specification
Possible Material Grades	40Cr, 42CrMo, AISI 4140, or other approved grades
Manufacturing Process	Forging, heat treatment, precision machining
Surface Treatment	Hard chrome plating or other specified finish
Overall Length	Model- and drawing-dependent
Rod Diameter	Model-dependent
Connection Type	Crosshead-side and piston-rod-side interfaces; verify drawing
Thread Specification	Subject to pump model
Surface Roughness	According to approved drawing and sealing requirements
Compatible Components	Crosshead, clamp, piston rod, stuffing-box seals
Quality Inspection	Dimensional, material, and surface inspection as agreed
Applicable Standard	API 7K only where specified and supported by documentation
Application	Oil and gas drilling mud pump systems

Technical note: Material grades and surface treatments shown are possible options found in the market, not universal specifications. Confirm the exact grade, hardness, coating, dimensions, and inspection requirements for the required pump model.

Extension rods may be available for selected models from manufacturers including BOMCO EMSCO Honghua Gardner Denver National Oilwell IDECO and other drilling pump suppliers. Potential model families include: - F-series mud pumps including selected F-500 F-800 F-1000 F-1300 and F-1600 configurations - 3NB-series mud pumps - Gardner Denver PZ-series pumps - Selected National and IDECO pump models Compatibility must be confirmed by the exact pump model OEM part number dimensions connection design and sealing arrangement. The listed manufacturers and model families are examples of possible applications not a guarantee of interchangeability.

Mud Pump Extension Rods

Product Overview

Mud Pump Extension Rods, also known as Pony Rods or Intermediate Rods in some applications, are mechanical connecting components used in reciprocating drilling mud pumps. They typically connect the power-end crosshead to the fluid-end piston rod, transmitting reciprocating motion and axial loads during pump operation.

Because extension rods experience repeated mechanical loading, accurate dimensions, reliable connections, and suitable surface properties are important for operational performance. The rod must match the pump's crosshead, clamp, piston rod, and sealing arrangement.

Key Features

• Alloy steel construction: Available in specified forged alloy steel grades such as 40Cr, 42CrMo, or other approved materials, depending on the design.

• Heat treatment: Applied according to the required mechanical properties and technical specification.

• Precision machining: Critical diameters, shoulders, threads, and connecting surfaces manufactured to the applicable drawing.

• Surface treatment options: Hard chrome plating or other specified finishes may be available for suitable designs.

• Replacement supply: Options for selected F-series, 3NB-series, PZ-series, and other compatible mud pump models.

• Drawing-based customization: Replacement components can be evaluated using OEM part numbers, technical drawings, dimensions, or approved samples.

Typical Applications

Mud Pump Extension Rods are used in drilling mud circulation systems on land-based and offshore drilling rigs. They are commonly supplied for routine maintenance, pump overhaul, and replacement of worn or damaged connecting components.

Ordering and Technical Verification

Please provide the pump manufacturer and model, OEM part number, overall length, major diameters, connection and thread details, and required material or surface treatment.

Before installation, confirm dimensional interchangeability, material requirements, surface finish, and compatibility with the existing piston rod and sealing system. Any API-related compliance claim should be supported by the applicable product and supplier documentation.