Top OEMs for Automatic Valves

1. Introduction

In the hydraulic architecture of municipal and industrial water systems, automatic valves function as the primary logic gates for hydraulic control. Unlike isolation valves (gate, butterfly, ball) which are static in their operation (either open or closed), automatic valves are dynamic, modulating devices designed to regulate pressure, flow, level, or surge conditions autonomously. These devices are critical for Non-Revenue Water (NRW) reduction, asset protection against water hammer, and maintaining consistent service levels in potable water distribution and wastewater force mains.

The term “automatic valve” in this context broadly encompasses hydraulic pilot-operated control valves—often diaphragm or piston actuated—as well as specialized passive automatic devices such as check valves and pinch valves used for process control. These valves operate on the differential pressure of the line fluid itself, requiring no external power source for basic function, though many modern iterations integrate solenoids for SCADA interface.

Read more4D-Printed Smart Materials For Water Treatment

From a regulatory and design standpoint, the selection of the Original Equipment Manufacturer (OEM) for these components is not merely a procurement detail; it is a fundamental engineering decision that dictates the system’s long-term hydraulic stability. The Safe Drinking Water Act (SDWA) and various state-level environmental mandates place a premium on system integrity. An automatic valve that fails to regulate pressure can lead to pipe bursts and contaminant intrusion. Conversely, a valve that hunts or chatters due to poor pilot design or sizing can induce fatigue failure in downstream infrastructure.

For consulting engineers and utility operators, the challenge lies in distinguishing between manufacturers based on engineering merit—casting quality, pilot precision, material compatibility, and support for complex hydraulic modeling—rather than brand familiarity. This article provides a technical, specification-focused analysis of the leading OEMs in the automatic valve sector, evaluating their suitability for rigorous municipal and industrial service.

2. How to Select This Valve Type

Read moreActivated Carbon Filtration in Water: Essential for Clean, Safe Drinking Supplies

Selecting an automatic valve requires a granular analysis of system hydraulics. Unlike on/off valves, control valves interact dynamically with the fluid column. Improper selection often results in cavitation, noise, vibration, and premature failure. Engineers must move beyond nominal pipe size (NPS) and specify based on flow coefficients ($C_v$), rangeability, and material science.

Valve Function and Hydraulic Duty Cycle

The first step in specification is defining the control variable. Is the valve intended for Pressure Reducing (PRV), Pressure Sustaining/Relief (PSV), Flow Control, Level Control (Altitude), or Surge Anticipation?

Once the function is defined, the duty cycle must be analyzed. A PRV in a main distribution line sees continuous modulation, whereas a deluge valve or surge relief valve may sit static for months before requiring millisecond-response actuation.
Rangeability: A critical engineering metric is the ratio of maximum to minimum controllable flow. Municipal systems often experience high demand during the day and near-zero demand at night. If a valve is sized solely for fire flow (peak), it may operate in a “cracked open” position during low flow, leading to wire-drawing (seat erosion) and instability. Engineers should look for OEMs offering rolling diaphragm technology or dual-chamber designs that maintain stability at low flow rates.

Pressure Conditions and Cavitation

The differential pressure ($Delta P$) across the valve determines the potential for cavitation. As fluid accelerates through the valve restriction, pressure drops. If it drops below the vapor pressure of the liquid, bubbles form. As pressure recovers downstream, these bubbles collapse with significant energy, causing pitting and noise.

Engineers must calculate the Sigma ($sigma$) cavitation index for the application. If the application falls into a cavitation zone, the specification must mandate anti-cavitation trim. This usually involves slotted cages or stacked plates that stage the pressure drop, keeping local pressures above vapor pressure.

Materials of Construction

Body Materials: Ductile iron (ASTM A536) is the standard for municipal water, typically coated with fusion-bonded epoxy (FBE) to AWWA C550 standards. For aggressive industrial wastewater or seawater applications, specifications should upgrade to Nickel-Aluminum-Bronze or Duplex Stainless Steel.
Elastomers: The diaphragm and seals are the primary wear parts. EPDM is standard for potable water (chloramine resistance), while Buna-N (Nitrile) is preferred for wastewater containing hydrocarbons or oils.
Pilot System: The pilotry is the “brain” of the valve. In corrosive environments or vaults prone to flooding, specifying 316 Stainless Steel tubing and fittings rather than copper or brass is essential to prevent external corrosion and pilot failure.

Sealing Mechanisms and Actuation

Globe vs. Angle Body: While globe bodies are standard for inline piping, angle bodies offer lower head loss and can replace an elbow in the piping isometric, saving space in pump stations.
Diaphragm vs. Piston:

• Diaphragm Actuators: Preferred for water service due to lower friction, zero leakage, and simpler maintenance. They are less sensitive to particulates than pistons.
• Piston Actuators: Often used in high-pressure applications or where very linear control characteristics are required, but they are more susceptible to seizing if particulates get between the piston and liner.

Single vs. Double Chamber: A single-chamber valve uses line pressure on top of the diaphragm to close against upstream pressure. A double-chamber valve allows pressure to be applied to both sides of the diaphragm, providing positive control for both opening and closing. Double-chamber designs operate more smoothly at lower differential pressures and eliminate the need for a check feature in some applications.

Maintenance and Serviceability

Operational Expenditure (OPEX) is driven by ease of service. Engineers should evaluate:

• Top Entry Design: Can the cover be removed and the diaphragm/trim replaced without removing the valve body from the line?
• Pilot Strainers: Pilot lines are susceptible to clogging. High-quality specifications require large-surface-area strainers (often “Y” strainers) on the pilot supply line, ideally with a blow-off valve for easy cleaning.
• Jack-Screw Holes: On large valves, cover plates are heavy and under spring tension. Jack-screw holes are a safety feature for maintenance personnel.

3. Comparison Table

The following table provides a technical comparison of the leading OEMs for automatic valves. This data is intended to assist engineers in matching specific hydraulic challenges with the manufacturer’s core competencies. This is not a ranking of quality, as all listed manufacturers produce specification-grade equipment. Instead, it highlights the engineering focus and best-fit applications for each OEM.

4. Top OEM Manufacturers

The following section details the specific engineering characteristics of the five validated OEMs for automatic valves.

Cla-Val

Overview: Cla-Val is widely considered the benchmark for automatic control valves in the North American municipal water market. Their designs are based on the Hytrol (100-01) main valve, a hydraulically operated, diaphragm-actuated globe or angle pattern valve.

Engineering Focus: Cla-Val excels in versatility. By altering the pilot sub-assembly, the same main valve body can function as a pressure reducer, pressure retainer, surge anticipator, or level controller. A significant engineering advantage is their casting quality and the availability of diverse materials, including Monel and Titanium for extreme environments.

Technical Highlights:

• Anti-Cavitation (KO) Trim: This radial slotted cage design directs impinging flow toward the center of the recovery chamber, mitigating damage to the valve body during high pressure drops.
• Electronic Control: Their 340-series pilots and VC-22D controllers allow for seamless SCADA integration, enabling remote setpoint changes and flow modulation based on time or demand (critical for advanced pressure management).
• Fueling & Fire: Beyond water, Cla-Val holds a dominant position in aviation fueling and deluge fire systems, indicating a high reliability standard.

Bermad

Overview: Bermad brings a distinct design philosophy centered on double-chamber hydraulic actuation. While they offer single-chamber valves, their expertise lies in the “active” control provided by the double-chamber architecture.

Engineering Focus: The double-chamber design separates the control chamber from the line pressure. This allows the valve to be powered open or closed by an external source or the line pressure itself, providing immediate response without the “lag” sometimes associated with spring-return single-chamber valves. This is particularly advantageous in pump control applications where rapid opening/closing sequences are required to prevent surges.

Technical Highlights:

• 700 Series: Their flagship municipal valve featuring a “Y” pattern body, which offers a hydrodynamic flow path with high flow capacity and low head loss compared to standard globe valves.
• Composite Valves: Bermad is a leader in using engineered plastics for control valves in corrosive environments or smaller utility applications, offering chemical resistance that metal valves cannot match.
• Wastewater Capability: They offer specialized control valves designed to handle solids and wastewater, utilizing remote hydraulic commands to keep electronics out of the vault.

Singer Valve (Mueller)

Overview: Now a brand under Mueller Water Products, Singer Valve has historically distinguished itself through innovation in low-flow stability and cavitation management. Their engineering philosophy focuses heavily on solving the “hunting” issues prevalent in distribution networks.

Engineering Focus: Singer is renowned for the Rolling Diaphragm. Unlike a standard flat diaphragm which can warp or distort at low valve openings, the rolling diaphragm maintains a constant effective area throughout the stroke. This results in incredibly stable modulation down to near-zero flow, eliminating the need for a secondary low-flow bypass valve in many PRV stations.

Technical Highlights:

• Anti-Cavitation Cages: Singer’s dual-cage technology fights cavitation by breaking the pressure drop into two stages. The cages are designed to contain the vapor collapse within the cage center, away from metal surfaces.
• Single Rolling Diaphragm (SRD): This technology provides linear control and reduces hysteresis, making the valve highly responsive to small pressure fluctuations.
• Pilot System: Singer pilots are often praised for their robust construction and ease of setting. Their 106-PG main valve is the platform for almost all their control configurations.

Red Valve / Tideflex

Overview: Red Valve and its Tideflex division occupy a unique niche. They do not manufacture the complex pilot-operated globe valves typical of the other OEMs listed here. Instead, they specialize in pinch valves and passive check valves.

Engineering Focus: The core technology is elastomer engineering. Their valves are designed for fluids that destroy standard control valves: raw sewage, sludge, mine tailings, and stormwater.
Tideflex Check Valves: These are “duckbill” valves made entirely of fabric-reinforced elastomer. They require no external power, have no mechanical hinges or flappers to rust or seize, and are self-draining.
Control Pinch Valves: For throttling abrasive slurries or wastewater, Red Valve uses pneumatic or hydraulic pressure to squeeze a rubber sleeve. This provides linear flow control with zero dead volume and no obstruction to flow when open.

Technical Highlights:

• Solids Handling: The ability to close drop-tight around entrapped solids (rags, debris) makes them superior for wastewater pump stations.
• Hydraulic Characteristics: While they have different head loss curves than globe valves, the Tideflex design offers very low cracking pressure and prevents backflow in outfall lines without the risk of “sticking” open.
• Mixing Systems: Their TMS (Tideflex Mixing System) utilizes the valve nozzles to improve water quality in storage tanks.

Flomatic Corporation

Overview: Flomatic is a highly integrated manufacturer, notable for owning their own foundry operations, which allows for strict quality control over lead-free bronze and stainless steel castings. While famous for check valves, they are a major player in the automatic control valve space for pump and pressure applications.

Engineering Focus: Flomatic focuses on robustness and solving specific pump control problems. Their Cycle Gard series is a staple in the industry for constant pressure pump control, eliminating the effects of pump cycling and water hammer.

Technical Highlights:

• Cycle Gard (CIV): These valves maintain a constant downstream pressure regardless of pump flow, allowing a fixed-speed pump to operate like a variable speed system within certain hydraulic limits. They feature a unique stop that prevents the valve from closing completely, ensuring minimum cooling flow for the pump.
• Unleaded Bronze: Flomatic was an early pioneer in unleaded alloys for potable water compliance, ensuring all wetted parts meet strict NSF/ANSI 61 & 372 standards.
• Automatic Control Valves (C-Series): Their pilot-operated valves utilize a simplified design that is easy to service, often preferred in smaller municipal booster stations and rural water districts.

5. Application Fit Guidance

Successful engineering design relies on matching the specific strengths of an OEM to the application environment. Below are generalized “best-fit” scenarios based on field performance and design characteristics.

Municipal Water Distribution (Clean Water)

Primary Candidates: Cla-Val, Singer Valve, Bermad.
For standard Pressure Reducing Valves (PRV) stations, all three are excellent.

• Select Singer if the station handles extreme variations in flow (e.g., high fire flow + low night flow) to leverage the rolling diaphragm’s stability without a low-flow bypass.
• Select Cla-Val for large networks requiring uniformity of spare parts, advanced electronic metering integration, or extremely large valve sizes (up to 36″+).

Wastewater & Sludge Handling

Primary Candidates: Red Valve / Tideflex, Bermad.
Standard pilot-operated valves will clog instantly in raw sewage.

• Select Red Valve for check valve applications (pump discharge, outfall) and flow control of sludge where full-port passage is required to pass solids.
• Select Bermad (Wastewater Series) if precise hydraulic control (pressure reduction/relief) is required on a force main, as they offer specialized pilots and bodies designed to minimize clogging risks.

Pump Stations (Well & Booster)

Primary Candidates: Flomatic, Cla-Val.

• Select Flomatic for well pumps and booster stations requiring “Constant Pressure” control (Cycle Gard) or high-reliability foot valves and check valves.
• Select Cla-Val for complex Deep Well Pump Control valves that require solenoid interfacing to synchronize with motor starters (delay opening until pump creates pressure, close before pump stops).

High Pressure & Cavitation

Primary Candidates: Singer Valve, Cla-Val.
When $Delta P$ is high (e.g., dropping pressure from a high-elevation reservoir to a lower zone), standard bodies will fail.

• Select Singer for their dual-cage Anti-Cavitation technology, which is highly effective at containing cavitation damage.
• Select Cla-Val for their KO anti-cavitation trim, a proven solution in high-head applications.

6. Engineer & Operator Considerations

Installation Best Practices

Straight Pipe Runs: Turbulence is the enemy of stable control. A common specification mistake is placing an automatic valve immediately downstream of an elbow or isolation valve. Engineers should specify a straight pipe run of at least 5 pipe diameters upstream and 3 diameters downstream of the control valve. This ensures the velocity profile entering the valve is uniform, improving pilot accuracy.

Air Release: Air pockets trapped in the pilot system or the main valve cover can cause erratic operation and “spongy” control. Automatic air release valves should be installed at the high points of the piping immediately upstream of the control valve to prevent air binding.

Common Specification Mistakes

Oversizing: The most common error is sizing the control valve to match the line size. A 10-inch pipe does not automatically require a 10-inch PRV. If the valve operates consistently in the bottom 10-15% of its stroke, it will chatter and wear prematurely. Valves should be sized based on flow velocity and $C_v$ requirements, often resulting in a valve one or two sizes smaller than the main line (using reducers).

Ignoring Pilot Materials: In vault environments, condensation and groundwater are common. Specifying standard copper tubing for pilots can lead to external corrosion. For long-term reliability, specify 316 Stainless Steel tubing and fittings for all pilot assemblies.

Maintenance Access & Spare Parts

Isolation: Every automatic valve must be installed with isolation valves upstream and downstream to facilitate maintenance.
Spare Parts Strategy: Diaphragms and rubber seats have a shelf life and a service life. Operators should standardize on one or two OEMs within a distribution zone to minimize inventory. Mixing Cla-Val, Singer, and Bermad in the same pressure zone complicates the spare parts inventory and requires operators to learn multiple pilot adjustment procedures.

Operational Lessons: Water Quality

In systems with high mineral content or old unlined cast iron pipes, particulate matter can wreak havoc on pilots. While Y-strainers are standard, they require manual flushing. In areas with known debris issues, consider specifying “self-flushing” pilot filters or external commercial strainers upstream of the valve assembly.

7. Conclusion

The selection of an automatic valve OEM is a balance between hydraulic performance requirements and operational practicality. There is no single “best” manufacturer; rather, there is a best fit for a given set of hydraulic parameters.

Cla-Val offers the safety of ubiquity and a massive range of pilot options, making them the default for general municipal distribution. Singer Valve provides technically superior solutions for low-flow modulation and high-cavitation environments through their rolling diaphragm and cage designs. Bermad offers high-efficiency double-chamber designs and composite material options. Red Valve is the undisputed choice for handling solids and wastewater where mechanical mechanisms would fail. Flomatic delivers robust, high-quality solutions for pump control and well applications.

For the consulting engineer, the goal is to write a specification that is performance-based. By focusing on low-flow stability, cavitation indices, and material longevity, and by rigorously evaluating these five proven OEMs against those criteria, utilities can ensure resilient and reliable system operation for decades.