Top OEMs for Cone Valves

1. INTRODUCTION

In the hierarchy of valves utilized within municipal and industrial water infrastructure, the cone valve occupies a unique tier reserved for the most critical, high-consequence applications. Often referred to as rotary cone valves or conical plug valves, these devices are engineered to provide full-bore flow with negligible head loss while possessing the mechanical robustness to withstand extreme pressure differentials and velocities. They are distinct from standard plug valves due to their specialized lift-turn-reseat mechanism, which separates the seating surfaces prior to rotation, virtually eliminating friction and wear during operation.

Cone valves are predominantly found in large-scale treated water transmission mains, raw water intake systems, and high-head pump stations. Their primary function often centers on pump check service—controlling the acceleration and deceleration of the water column during pump startup and shutdown to mitigate water hammer. Additionally, they are frequently specified for reservoir isolation and, in specific configurations (such as fixed cone valves), for free discharge and energy dissipation applications.

The selection of an Original Equipment Manufacturer (OEM) for cone valves is a decision of significant engineering weight. Unlike commodity gate or butterfly valves, cone valves are capital-intensive assets, often custom-engineered for specific hydraulic transients. They are expected to remain in service for 50 to 70 years, often outlasting the pumps they protect. A failure in a cone valve—whether due to mechanism seizure, seat failure, or actuation inadequacy—can lead to catastrophic surge events, flooding, and extended plant downtime. Therefore, the evaluation of OEMs must move beyond initial price to focus on metallurgical quality, mechanical design pedigree, hydraulic transient capability, and long-term serviceability.

2. HOW TO SELECT THIS VALVE TYPE

Selecting a cone valve requires a rigorous engineering analysis of the system’s hydraulic profile and the valve’s mechanical duties. Because cone valves are often the last line of defense against hydraulic transients, the specification process must be detailed and precise. The following criteria are essential for consulting engineers and utility decision-makers.

Valve Function and Duty Cycle

The first step in selection is defining the primary function: pump control (check service), shut-off (isolation), or throttling (flow control).

• Pump Check Service: This is the most common application for rotary cone valves. The valve must be synchronized with the pump motor. The selection focuses on the valve’s ability to open slowly to prevent upsurge and close at a two-stage speed (fast then slow) to prevent slamming and water hammer. The “lift-turn-reseat” mechanism is critical here to prevent seat galling during frequent cycling.
• Isolation: For guard valves located upstream of turbines or downstream of reservoirs, the valve may sit idle for months. Selection criteria here favor long-term seat integrity and the ability to operate reliably after long periods of dormancy.
• Free Discharge (Fixed Cone): Distinct from rotary cone valves, fixed cone (Howell-Bunger) valves are used for releasing water to atmosphere. Selection depends on energy dissipation requirements and spray containment (hoods).

Pressure and Flow Conditions

Cone valves are characterized by their 100% port area, meaning the internal diameter of the valve matches the pipe diameter. This results in a discharge coefficient (Cd) approaching that of a straight pipe. Engineers must evaluate:

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• Head Loss Requirements: If pumping costs are a major lifecycle factor, the cone valve is superior to butterfly or globe valves due to near-zero head loss when fully open.
• Velocities: Cone valves can handle velocities exceeding 25-30 ft/s (7.5-9 m/s), where other valves would suffer from vibration or cavitation.
• Cavitation Index: While cone valves have excellent flow characteristics, throttling at partial openings can induce cavitation. The valve body design and downstream pressure conditions must be analyzed to ensure the valve operates within safe sigma limits.

The Lift-Turn-Reseat Mechanism

The core differentiator of a rotary cone valve is its operating mechanism. When an open command is received, the plug is mechanically lifted (axially) off the seats. It then rotates 90 degrees to the open position. Finally, it may lower slightly or lock in position. The reverse happens on closing.

Engineers must scrutinize the OEM’s design of this linkage. It is usually a complex arrangement of crossheads, rollers, and screws inside the operator housing. Designs that house this mechanism in a clean, oil-bath environment are preferable to those exposed to the process media. The mechanism must be robust enough to overcome the “unbalanced torque” caused by high differential pressures.

Materials of Construction

Given the longevity requirements, material specifications are non-negotiable:

• Body and Plug: typically ASTM A536 Ductile Iron or ASTM A216 Cast Steel for higher pressures. Cast iron is generally obsolete for modern high-pressure cone valves.
• Seating Surfaces: This is the critical wear point. Specifications should call for Monel (nickel-copper alloy) or 316 Stainless Steel welded overlays. Monel is often preferred for its resistance to galvanic corrosion and galling when paired with stainless steel components.
• Bearings: Permanently lubricated, corrosion-resistant sleeve bearings (e.g., bronze or stainless steel with PTFE lining) are standard to ensure the plug does not bind.

Actuation and Control

Cone valves require significant torque to operate, particularly during the seating and unseating phases.

• Hydraulic Actuation: The industry standard for pump check service. Hydraulic cylinders utilize system pressure or an independent Hydraulic Power Unit (HPU). The incompressibility of hydraulic fluid allows for precise speed control (two-speed closing) essential for surge suppression.

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• Electric Actuation: Used primarily for isolation valves where closing speed is less critical. However, they must be sized to handle the “breakaway” torque required to lift the plug.
• Manual Operation: Required as a backup. Due to the high gear ratio needed to lift and turn the heavy plug, manual operation is slow and labor-intensive, suitable only for emergency or maintenance scenarios.

Maintenance and Serviceability

Engineers must consider access to the operating mechanism. Top-entry or side-entry access ports allow maintenance personnel to inspect the lift-turn linkage without removing the massive valve from the line. Furthermore, the ability to replace stem packing under pressure is a safety feature that should be specified.

3. COMPARISON TABLE

The following table provides a comparative overview of the leading OEMs in the cone valve market. This data is intended to assist engineers in matching specific project requirements—such as valve type (Rotary vs. Fixed), pressure class, and application focus—with the appropriate manufacturer capabilities. This is not a ranking, but a guide to understanding the distinct engineering philosophies and portfolio strengths of each OEM. Note that “Rotary Cone” refers to pump check/isolation valves, while “Fixed Cone” refers to energy dissipation/discharge valves.

4. TOP OEM MANUFACTURERS

The following section details the specific capabilities and engineering characteristics of the four primary OEMs dominating the cone valve sector. Evaluation is based on technical merit, portfolio breadth, and historical performance in water and wastewater applications.

VAG

VAG is a global heavyweight in the valve industry, with a particularly strong reputation in the dams and hydropower sector. Their approach to cone valves is deeply rooted in German engineering principles, prioritizing hydrodynamic efficiency and durability under extreme pressures.

Technical Characteristics:
VAG’s portfolio includes both rotary control valves and fixed cone discharge valves. Their rotary cone designs are often utilized in the most demanding transmission scenarios where pressures exceed standard municipal ratings. VAG valves typically feature robust body construction designed to minimize elastic deformation under high loads, which is critical for maintaining seal integrity in large diameters. Their KSS and RKV series (plunger/needle types often categorized alongside cones for control) are engineered to handle high pressure drops without cavitation damage.

Best-Fit Scenarios:
VAG is an optimal choice for projects involving high-head dams, bottom outlets, or complex transmission mains requiring sophisticated energy dissipation. They are also strong contenders for applications requiring high-level actuation integration, as they offer complete packages including weight-loaded hydraulic actuators for fail-safe operation.

Orbinox

While Orbinox is globally recognized for knife gate valves, their acquisition of specific dam and hydraulic works divisions has positioned them as a key player in the cone valve market, specifically regarding Fixed Cone Valves (often referred to as Howell-Bunger valves).

Technical Characteristics:
Orbinox’s primary strength in this category lies in free-discharge applications. Their fixed cone valves are designed to regulate flow from reservoirs or dams by discharging water into the atmosphere in a hollow cone-shaped jet. This design maximizes air entrainment and energy dissipation, protecting the downstream environment from scour. The sleeve operation is typically driven by twin hydraulic cylinders or electric actuators.

Best-Fit Scenarios:
Orbinox is the manufacturer of choice for reservoir level control, turbine bypass, and ecological flow release. Engineers should specify Orbinox when the application calls for atmospheric discharge rather than inline pump check service. Their custom engineering capabilities allow for various hood designs (concentrators) to control the spray pattern, which is vital for preventing erosion on canyon walls or spillways.

DeZURIK

For North American municipal engineers, DeZURIK (specifically through their APCO and Willamette heritage brands) represents the industry standard for Rotary Cone Valves used in pump check service. The acquisition of these legacy brands has consolidated a vast amount of hydraulic expertise under the DeZURIK umbrella.

Technical Characteristics:
The DeZURIK/APCO rotary cone valve is defined by its precise lift-turn-reseat mechanism. The valve plug is fully lifted off the seat before rotation begins, ensuring zero contact during the stroke. This feature is paramount for pump stations where the valve may cycle daily. They offer full 100% port areas, ensuring the lowest possible head loss of any valve type. The seating is typically metal-to-metal (Monel on Stainless), designed to last decades without replacement.

Best-Fit Scenarios:
DeZURIK is the “specification-safe” choice for municipal clean water pump stations. They are ideally suited for pump discharge applications requiring two-speed closing logic to control surge. The availability of parts, service manuals, and local engineering support for the APCO/Willamette designs makes them a favorite for long-term maintainability in municipal utilities.

Flowserve

Flowserve occupies the heavy industrial and mega-project end of the spectrum. With a lineage that includes Worthington and Allis-Chalmers, Flowserve supports some of the largest water infrastructure in the world. Their cone valves are often custom-engineered behemoths designed for specific, non-standard operating conditions.

Technical Characteristics:
Flowserve cone valves are characterized by massive construction and custom hydraulic actuation systems. They excel in applications requiring diameters exceeding 72 inches or pressures that defy standard AWWA tables. Their designs often incorporate advanced trunnion mounting and proprietary bearing materials to handle the immense radial loads generated by high-velocity flows in large conduits.

Best-Fit Scenarios:
Flowserve is best suited for large-scale raw water intakes, nuclear power cooling circuits, and major municipal aqueducts where off-the-shelf solutions are insufficient. If a project involves replacing a 50-year-old Allis-Chalmers cone valve, Flowserve often holds the original drawings and engineering data, making them a critical partner for rehabilitation projects.

5. APPLICATION FIT GUIDANCE

To ensure system reliability, engineers must align the OEM’s specific strengths with the application at hand. The following breakdown provides guidance on where each manufacturer typically excels.

Municipal Water Distribution (Pump Stations)

Preferred: DeZURIK, Flowserve.
For the classic pump check application in finished water pumping, the rotary cone valve is the gold standard. DeZURIK (APCO/Willamette) is widely specified due to its standardized designs that align with AWWA C506 (historically) and modern municipal specs. Flowserve is preferred for very large stations (e.g., >60 inch lines) or where legacy equipment matches their portfolio. The key requirement here is the lift-turn-reseat mechanism to survive frequent cycling.

Reservoir Discharge & Energy Dissipation

Preferred: Orbinox, VAG.
When the goal is to release water from a dam or tank into a river or basin, the Fixed Cone Valve is the correct tool. Orbinox and VAG excel here. Their designs focus on the sleeve mechanism and flow hoods necessary to dissipate energy without destroying the valve or the civil structure. Rotary cone valves are generally not used for free discharge due to the potential for seat damage at high velocities.

High-Pressure Transmission & Hydropower

Preferred: VAG, Flowserve.
In mountainous terrain or long-distance transmission where static heads are extreme, VAG’s high-pressure engineering pedigree is advantageous. Their valves are designed to handle the massive unbalanced forces found in these systems. Flowserve also competes strongly here, particularly in the power generation sector.

Rehabilitation of Legacy Infrastructure

Preferred: DeZURIK, Flowserve.
Many US water treatment plants built in the 1950s-1970s utilize Chapman, Willamette, or Allis-Chalmers cone valves. DeZURIK (holding Willamette/APCO IP) and Flowserve (holding Allis-Chalmers IP) are the logical choices for sourcing OEM parts or drop-in replacements that match existing face-to-face dimensions and flange patterns without requiring piping modifications.

6. ENGINEER & OPERATOR CONSIDERATIONS

Specifying the right OEM is only the first step. The long-term success of a cone valve installation depends heavily on installation details, maintenance strategies, and operational protocols.

Installation Best Practices

Cone valves are exceptionally heavy. A 36-inch cone valve can weigh tens of thousands of pounds. Engineers must specify a concrete plinth or sole plate capable of supporting the dead load and the dynamic loads during operation.

• Grouting: The valve base must be fully grouted to prevent vibration transmission. Partial support can lead to body distortion, which will bind the precision lift-turn mechanism.
• Actuator Support: Large hydraulic cylinders often require their own independent support structures. Cantilevering a heavy cylinder off the valve operating nut can cause seal failure or stem bending over time.
• Orientation: While cone valves can technically be installed vertically, horizontal installation is preferred for maintenance access to the bearings and operating mechanism.

Maintenance Access and Mechanics

The most common failure mode for cone valves is the seizure of the lift-turn mechanism due to lack of lubrication or water intrusion into the gearbox.

• Mechanism Hygiene: Operators must regularly inspect the operating housing. If the design is oil-bath lubricated, oil analysis should be performed annually to check for water ingress (emulsification) or metal shavings.
• Exercise Programs: Isolation cone valves that sit open for years will eventually freeze. Utilities must implement a quarterly or semi-annual exercise program where the valve is cycled partially (e.g., 10%) to redistribute grease and verify the lift mechanism functions.
• Spare Parts: Due to the custom nature of these valves, lead times for parts like crosshead rollers or stem nuts can be months. Plants should keep critical linkage components and soft seal kits in inventory.

Common Specification Mistakes

Undersizing the Actuator: The torque required to unseat a cone valve under maximum differential pressure is massive. Engineers often calculate torque based on running conditions, failing to account for the “breakaway” torque and the mechanical advantage needed to lift the plug. This results in valves that stall during emergency closure events.

Ignoring Cavitation at Partial Openings: While cone valves are great for full flow, using a standard rotary cone valve for prolonged throttling can destroy the metal seats. If throttling is required, specifying a valve with reduced port or anti-cavitation trim (or switching to a plunger valve) is necessary.

7. CONCLUSION

The cone valve remains the premier choice for critical water applications where failure is not an option. Its ability to provide full flow with minimal head loss, coupled with a robust metal-seated design, offers a lifecycle value that cheaper valve types cannot match. However, the complexity of the lift-turn-reseat mechanism demands that engineers select OEMs with proven manufacturing pedigrees and deep engineering support.

For municipal pump check service, DeZURIK and Flowserve offer the robust rotary designs that have defined the industry for decades. For free discharge and high-head control applications, VAG and Orbinox provide specialized solutions that manage energy dissipation effectively.

Ultimately, the successful deployment of a cone valve relies on a partnership between the consulting engineer and the OEM. By clearly defining the hydraulic transients, understanding the distinction between rotary and fixed designs, and planning for the long-term maintenance of the operating mechanism, utilities can ensure these massive assets protect their infrastructure for generations.