Pump Heads

The pump head is the central component of a plunger pump. Here, the fluid is pressurized and transferred into the discharge line. Acting as the connection between the mechanical drive (crank mechanism) and the fluid circuit, the pump head contains the main fluid-handling components, including inlet and outlet valves, seals, and plunger guides.

Its design determines how much pressure the pump can generate, the achievable flow rates, and which media can be handled reliably. Since plunger pumps are used in a wide range of applications, there are many different designs of pump heads – adapted to pressure level, flow rate, and the properties of the pumped medium.

The construction of a pump head depends heavily on the combination of pressure and flow rate. A pump head designed for 100 l/min at 1,000 bar differs fundamentally from one designed for 1,000 l/min at 100 bar – even if both pumps have the same drive power.

The characteristics of the pumped liquid also play a key role. Fluids containing abrasive particles or solids require a different design than clean, filtered media.

Material selection is another crucial factor. Experience has shown that coated pump heads made from inexpensive base materials tend to wear quickly, as the protective coating is abraded by the motion of the plungers and seals. Because of this, KAMAT uses solid, high-quality materials such as stainless steel, duplex or super duplex steels, and special alloys like Inconel when required.

Pump heads can vary depending on the manufacturer and application. The main design types include:

• One-piece pump heads: Compact and robust, with fewer sealing points, reducing the risk of leakage and minimizing maintenance.
• Multi-piece pump heads: More cost-effective to produce but require more seals and service work, increasing the potential for leaks.
• Coated pump heads: Initially low-cost, but coatings may detach under high temperature or with abrasive media, leading to premature wear.
• Internal vs. external valve arrangement: The valve position affects how sensitive a pump head is to contamination and how easy it is to clean.

Pump heads are designed differently depending on the required pressure and flow combination. At lower pressures, the focus is on high flow rates, while at very high pressures, material strength and stress reduction are key. The choice of valves, cylinder bore design, and materials all vary significantly to meet these demands.

Pump heads in this range typically operate up to about 250 bar and are used where large volumes of liquid must be conveyed – for example, in cleaning systems or cooling water circuits. To enable high flow rates, the cylinder and plunger diameters are relatively large. However, this design reduces structural strength, which is why cast materials are commonly used due to their cost efficiency and ease of machining.

A more durable yet complex solution is the use of forged blocks, which provide higher material quality and strength. The sizing of the inlet and outlet valves is also essential: they must have large cross-sections to ensure slow fluid velocity and prevent cavitation. For maintenance, it’s beneficial when the suction valves are easily accessible, as they typically wear faster than discharge valves.

The medium-pressure range extends up to about 1,000 bar. Typical applications include water hydraulics, pipe and sewer cleaning, and descaling in the steel industry. Forged pump heads are preferred in this range because they withstand high pressure peaks and are less prone to cracking, corrosion, or leakage than cast or segmented designs.

Descaling applications often circulate large water volumes that contain tiny, hard particles even after filtration. For this reason, special wear-resistant valves are used to ensure long-term operational safety. Thanks to their robust design, pump heads in this pressure range can operate reliably even at high stroke frequencies.

For pressures above 1,000 bar – for example, in high-pressure water jet cutting or specialized industrial processes – particularly durable pump head designs are required. Under these extreme conditions, the housing must be engineered to minimize cyclic stresses. Only small, highly stressed parts such as plunger guides or valve seats are made from ultra-high-strength alloys.

A central design objective is to minimize the dead volume in the cylinder. This residual volume must be compressed before the full discharge pressure is reached, which reduces volumetric efficiency and increases pressure pulsation. Optimized geometries ensure that the high-pressure pump remains stable and efficient even under extreme operating conditions.

As operating pressures increase, so do the stresses acting on the pump head. A high-performance pump head must therefore meet several critical requirements:

• Resistance to fluctuating operating pressures: The material must withstand pressure variations with every stroke.
• Cavitation resistance: Poor flow conditions can create vapor bubbles that collapse and damage surfaces. A well-designed pump head minimizes cavitation.
• Resistance to aggressive media: Chemically demanding or abrasive fluids require materials that prevent corrosion and wear.
• Ease of maintenance: Since valves, seals, and plunger guides are wear parts, the pump head should allow quick access to these components without full disassembly.
• Long service life with minimal wear: Precision manufacturing and high-quality materials ensure reliable operation even in continuous use.

In industrial environments where downtime leads to high costs, the quality and durability of a pump head are essential for overall reliability. For this reason, KAMAT relies exclusively on forged pump heads made of premium stainless steels or special alloys, designed with minimal sealing points to reduce maintenance requirements.

KAMAT designs and manufactures pump heads for plunger pumps tailored to a wide variety of industrial requirements. High-quality materials and well-engineered designs ensure long service life and operational safety, even with abrasive fluids or extreme pressures.

A key advantage of KAMAT pumps is its modular system. Along with the gearbox and fluid end assemblies, pump heads form one of the core modules of this system. This modularity allows pump heads to be flexibly configured, replaced, or upgraded without having to replace the entire pump. This simplifies maintenance, reduces downtime, and enables easy adaptation of existing high-pressure pumps to new applications.

The modular pump heads offer several technical benefits:

• Modularity and standardization: Each pump is based on a defined gearbox size. Pump heads are standardized modules that can be reconfigured, allowing for individual setups up to 3,500 bar and 1,500 kW.
• Adaptation to fluid and pressure range: Depending on the application, different materials and valve types can be selected – for example, the M-head (up to about 1,000 bar) and the A-head (up to 3,500 bar), as well as various valve configurations.
• High spare parts availability: Standardized assemblies ensure fast availability of pump heads and components, simplifying service and maintenance.
• On-site variant management: Pump heads can be exchanged or retrofitted directly in the system without extensive modification work.

This makes KAMAT pump heads not only robust core components but also flexible modules that integrate seamlessly into a wide range of industrial applications – reliable, durable, and future-ready.

Within KAMAT’s modular system, there are two pump head variants that cover all requirements from medium to ultra-high pressure ranges: the M-head and the A-head.