Bermad Top Pilot Control Valves: Precision Pressure Management for Irrigation Systems

Introduction

Pressure management is one of the most critical aspects of irrigation system design. Too much pressure damages drippers, blows joints, and wastes water through misting. Too little pressure results in uneven distribution and under-irrigation. In large or complex systems — particularly those with significant elevation changes, long pipe runs, or multiple zones operating at different pressures — maintaining consistent, controlled pressure throughout the system requires more than a simple pressure regulator.

Bermad is one of the world's leading manufacturers of hydraulic control valves, trusted by irrigation engineers, water utilities, and industrial operators across the globe. Their top pilot (TP) control valve range offers precise, reliable pressure management for demanding irrigation applications, combining robust construction with sophisticated hydraulic control in a compact, field-serviceable package.

IrriSmart stocks the Bermad 100 and 200 Series top pilot control valves, and this guide explains how they work, what makes them different from standard pressure regulators, and how to choose the right valve for your system.

What Is a Top Pilot Control Valve?

A Bermad top pilot control valve is a hydraulically operated diaphragm valve that uses a small pilot valve mounted on top of the main valve body to control its operation. The pilot valve senses the downstream pressure and modulates the main valve opening to maintain a precise set pressure — regardless of changes in upstream pressure or downstream flow demand.

This is fundamentally different from a simple inline pressure regulator, which uses a spring-loaded mechanism that can be less accurate and less responsive to pressure fluctuations. The Bermad top pilot design offers:

• Greater accuracy — the pilot valve responds to actual downstream pressure, not just spring tension
• Better stability — the diaphragm valve opens and closes smoothly, avoiding the pressure hunting that can occur with spring regulators
• Higher flow capacity — the full-bore diaphragm design minimises pressure loss across the valve at normal flow rates
• Field serviceability — the diaphragm and pilot valve can be inspected and replaced without removing the valve body from the pipeline
• Versatility — the same valve body can be configured for different functions by changing the pilot valve

How a Top Pilot Valve Works

Understanding the operating principle helps with both selection and troubleshooting:

1. Water enters the valve body and also passes through a small control port into the chamber above the diaphragm
2. When the chamber above the diaphragm is pressurised, the diaphragm is pushed down, closing the main valve
3. The pilot valve on top of the main body controls whether the chamber above the diaphragm is pressurised (valve closed) or vented to downstream (valve open)
4. For a pressure reducing valve, the pilot senses downstream pressure: when downstream pressure is below the set point, the pilot vents the chamber and the main valve opens; when downstream pressure reaches the set point, the pilot pressurises the chamber and the main valve closes
5. This continuous modulation maintains a stable downstream pressure at the set point

The result is a valve that continuously and automatically adjusts its opening to deliver a precise, stable downstream pressure regardless of upstream pressure variation or changes in flow demand.

The Bermad 100 Series

The Bermad 100 Series is the entry-level top pilot control valve range, designed for straightforward pressure control applications in irrigation systems. It combines the reliability and precision of Bermad's hydraulic control valve technology in a compact, cost-effective package suitable for a wide range of horticultural and agricultural irrigation applications.

• Available in a range of sizes to suit common irrigation pipe diameters
• Hydraulically operated diaphragm design for smooth, accurate pressure control
• Field-serviceable without removing the valve from the pipeline
• Suitable for pressure reducing and zone control applications
• Robust construction for long service life in demanding field conditions

View the Bermad 100 Series | View the 100 Series Pressure Regulating

The Bermad 200 Series TP (Top Pilot)

The Bermad 200 Series TP is the more advanced range, offering greater flexibility and functionality for complex irrigation systems. The 200 Series TP valves are available in multiple configurations to suit different control requirements:

200 Series TP — Pressure Reducing (No Solenoid Control)

A hydraulically operated pressure reducing valve with top pilot control, designed for applications where automatic pressure reduction is required but solenoid (electric) zone control is not needed. The valve maintains a precise downstream pressure set by the pilot valve, regardless of upstream pressure variation.

Typical applications include:

• Pressure reduction at the head of a zone or sub-main to protect downstream drippers or sprinklers from excess pressure
• Pressure management on systems fed from elevated reservoirs or high-pressure mains where the source pressure exceeds the system's operating requirements
• Protecting sensitive components such as drip tape, micro-sprinklers, and fertigation equipment from pressure spikes

View the 200 Series TP Pressure Reducing (No Solenoid)

200 Series TP — Pressure Reducing (2-Way)

The 2-way configuration combines pressure reducing control with solenoid-operated zone control in a single valve body. This allows the valve to both regulate downstream pressure and be switched on and off by an irrigation controller — eliminating the need for a separate solenoid valve in each zone.

This is a particularly efficient solution for systems where each zone requires both pressure regulation and automated on/off control, as it reduces the number of valves, fittings, and potential leak points in the system.

Typical applications include:

• Automated irrigation zones where each zone operates at a different pressure or where source pressure is too high for direct zone valve use
• Drip irrigation systems on sloped terrain where pressure varies significantly between zones at different elevations
• Sports turf and amenity irrigation where precise, consistent pressure is required across multiple independently controlled zones

View the 200 Series TP Pressure Reducing (2-Way)

Pressure Reducing vs Pressure Regulating: What Is the Difference?

These terms are sometimes used interchangeably but have a specific meaning in the context of Bermad valves:

• Pressure reducing — the valve reduces and maintains a set downstream pressure, regardless of upstream pressure. If upstream pressure drops below the set downstream pressure, the valve opens fully. This is the most common configuration for irrigation pressure management.
• Pressure regulating — the valve maintains a set pressure differential or flow rate, rather than a fixed downstream pressure. Used in more specialised applications where flow regulation or differential pressure control is required.

Choosing the Right Bermad Valve for Your System

Use this guide to narrow down your selection:

• Need pressure reduction only, no automated zone control: Bermad 200 Series TP Pressure Reducing (No Solenoid)
• Need pressure reduction combined with automated on/off zone control: Bermad 200 Series TP Pressure Reducing (2-Way)
• Smaller system or simpler pressure control requirement: Bermad 100 Series
• Need pressure regulating (flow or differential pressure control): Bermad 100 Series Pressure Regulating

Setting and Adjusting the Pilot Valve

The downstream pressure set point is adjusted by turning the adjustment screw on the pilot valve. Increasing the spring tension raises the set pressure; decreasing it lowers the set pressure. Always use a pressure gauge downstream of the valve when setting or adjusting the pilot to confirm the actual downstream pressure.

Key tips for setting Bermad valves:

• Set the valve under normal operating flow conditions — pressure may differ at zero flow
• Make adjustments gradually and allow the system to stabilise before taking a reading
• Record the set pressure and number of turns from fully closed for future reference
• Check the set pressure at the start of each season and after any significant system changes

Installation Best Practices

• Install the valve with flow in the direction indicated by the arrow on the valve body
• Install isolation valves (ball valves) upstream and downstream of the Bermad valve to allow servicing without draining the system
• Install a pressure gauge downstream of the valve for monitoring and setting
• Install a strainer or filter upstream of the valve to protect the pilot valve orifice from blockage by particles — our Amiad Filters range includes suitable options
• Ensure the valve is accessible for periodic inspection and servicing

Maintenance

Bermad top pilot valves are designed for long service life with minimal maintenance. Key tasks include:

• Inspect the pilot valve annually — clean the orifice and check the needle and seat for wear
• Check the diaphragm for cracks or deformation every two to three years, or if the valve begins to leak or hunt
• Verify the set pressure at the start of each season using a downstream pressure gauge
• Flush the control tubing if the valve response becomes sluggish

Conclusion

Bermad top pilot control valves offer a level of precision, reliability, and versatility that simple spring-loaded pressure regulators cannot match. For irrigation systems where consistent pressure management is critical — whether to protect sensitive drip components, manage elevation-driven pressure variation, or combine zone control with pressure regulation — the Bermad 100 and 200 Series TP valves are the professional's choice.

Browse the full Bermad Control Valves range at IrriSmart, or contact our team for expert advice on specifying the right valve for your system.