Control Valve Trims
Copes Vulcan General Service and Severe Duty control valves offer a wide range of trims to solve industry’s most challenging problems. These include Cavitation, Severe Pressure Drop (i.e. Noise and heavy wear) and controllability. Copes Vulcan also has the largest portfolio of Desuperheaters in the World. This means that we are always able to offer the customer the most appropriate desuperheating technology. Typically we will match the characteristics of a cooling water valve to the requirement of the desuperheater thus using both valves to provide an optimal solution and the lowest possible approach temperature.
Extensive line of standard trims is offered in
both full size and numerous reduced sizes
Unbalanced Single Seat Plug Throttling:
A general purpose cage guided trim for on/off or modulating control. Designed for low to moderate pressure drop applications. The solid plug has a contour on its lower end that provides varying flow area with lift, thus regulating the flow. It can be used with a wide variety of non-abrasive/non-adhesive compressible and non-compressible fluids. Standard trim for valve sizes 1½” and smaller.
| Standard ANSI B16.104 Rated Seat Leakage | Class IV standard Class V optional |
| Standard Trim Characteristics | Modified parabolic, linear, equal percentage |
| Typical Flow Direction | Under the seat |
| Maximum Rangeability | 35-50:1 |
Unbalanced Single Seat Port Throttling:
A general purpose cage guided trim for on/off or modulating control where moderate flow rates exist along with low differential pressures. The unbalanced single seat plug modulates flow by uncovering ports in the cage. The cage porting produces the pressure drop or flow control. This trim can be used in most nonabrasive/non-adhesive compressible and non-compressible fluids,
| Standard ANSI B16.104 Rated Seat Leakage | Class IV standard Class V optional |
| Standard Trim Characteristics | Modified parabolic, linear, equal percentage |
| Typical Flow Direction | Under the seat |
| Maximum Rangeability | 35-50:1 |
Balanced Single Seat Port Throttling:
A general purpose cage guided trim for on/off or modulating control suitable for use in most non-abrasive/non-adhesive compressible and non-compressible fluid services.
The balanced plug design reduces actuator force requirements thus permitting the use of smaller, less expensive actuators while maintaining tight shut-off capability.
Designed for valves 2″ and larger and is a standard offering when the service temperature does not exceed the 400°F to 500°F range, relative to pressure.
| Standard ANSI B16.104 Rated Seat Leakage | Class IV standard Class V optional Class VI optional – Requires a soft seat |
| Standard Trim Characteristics | Modified parabolic, linear, equal percentage |
| Typical Flow Direction | Over the Seat |
| Maximum Rangeability | 35-50:1 |
CAV B9:
CAV B9 trim can be applied in liquid service where low level cavitation is evident. The radially step drilled cage design reduces the effects of cavitation along with the associated noise and erosion problems by forcing the cavitation to occur in the center of the cage, away from all metal surfaces.
By reversing the flow and having the fluid pass under the seat, CAV B9 can also be an effective trim for flashing applications.
Although numerous standard designs are available, the trim can be custom designed to provide various flow characteristics or optimal performance under specific operating conditions.
Available in valves 2″ and larger.
| Standard ANSI B16.104 Rated Seat Leakage | Class IV standard Class V optional |
| Standard Trim Characteristics | Modified parabolic, linear, equal percentage |
| Typical Flow Direction | Under the seat |
| Maximum Rangeability | 35-50:1 |
Cascade:
A cage guided plug throttle trim designed primarily for high pressure drop water applications where cavitation, vibration and excessive wear occur with conventional trims. The tapered plug fits into a cage and seat with a matching taper, thus small changes in flow occur with respect to plug travel resulting in extremely high rangeability. The labyrinth grooves machined into the plug’s taper create a series of orifices which reduces the total pressure drop in a series of stages. It is especially suited to applications where small flow rates must be controlled accurately.
Numbered Cascade Trim:
Copes-Vulcan’s numbered Cascade Trim assembly is used in Control valves where low flow rates and high turndown requirements prevail such as in desuperheater cooling water control. The cascade trim can be applied when differential pressures are as high as 1500 psi with service temperature as high as 1050°F. Exceptional tight shutoff can easily be maintained.
Port Throttling GAD Trim:
The Copes-Vulcan Port Throttling GAD trim was developed to meet the rigorous requirements of feedwater and feedwater start-up control. Designed to give optimum flexibility in power operated control valves, the trim is available in double seat, balanced single seat, and tandem versions.
The GAD trim is equally suitable for use with steam and many other fluids. It has been successfully used on high pressure water applications involving pressure of up to 5075 psi (350 Bar) and pressure differential of up to 3625 psi (250 Bar).
One stage HUSH:
One stage HUSH trim is a specialty trim designed to reduce noise associated with compressible fluids as well as to reduce the undesirable effects of flashing and cavitation that would occur with most single pressure drop trims. The HUSH cage consists of a single cylinder with a large number of radially drilled orifices* The fluid exits the orifices as low energy jets resulting in significant reductions in noise or erosion, Although numerous standard designs are available, one stage HUSH is often custom engineered to provide various flow characteristics or optimal performance under specific operating conditions.
Soft Seated Hush Trim:
The long-standing and high cost problem of leaking control valves in severe duty applications has been solved through the development of a unique soft seat trim design. It is not unusual for generating plants to lose up to 10% of capacity through leakage. Trim leakage often occurs in severe duty applications such as boiler feed pump recirculation valves. These valves typically are required to remain closed 95% of the time, against shut-off pressures of up to 5000 PSIG.
Copes-Vulcan’s Soft Seated HUSH@ Trim can save you money by preventing lost capacity, plus a substantial reduction in maintenance costs. Copes-Vulcan’s Engineering Center has developed and tested a patented soft seated trim which maintains zero (bubble tight) leakage throughout the service life of the trim.
The soft seated trim when used in conjunction with Copes-Vulcan’s “HUSH” Trim, reduces all likelihood of damaging cavitation.
The trim is designed for new as well as existing valve installations. Known as the Soft Seated HUSH Trim, the design is unique in that it uses a dual plug, with a primary plug engaging the soft seat and an inner plug engaging the secondary metal seat thereby preventing throttling at the soft seat.