Control valve retrofit

October 2001 Valves, Actuators & Pump Control

In many cases when an existing valve needs to be replaced in a plant, the valve body is still in good condition but the trim is no longer suitable, and in addition, the actuator and positioner need to be updated. In these cases Mitech can offer a retrofit service where it will fit new internals and top works to the original valve body.

Mitech trims will be designed to suit the application, and can be selected from the complete range right up to the energy dissipating disk stack. Materials are chosen for safe operation and long life.

Mitech has recently rebuilt eight 200 mm valves for an oxygen plant in a large petrochemical factory. The material used for the plug, seat and retainer was Monel K500, and the bonnet was manufactured in stainless steel to suit the bodies. New actuators and positioners were fitted to the valves. The object of the exercise was to improve safety in the plant and to provide a valve with tighter shut-off.

In 1995 and 1998 Mitech fitted soft-seated trims into some 400 mm flare stack valves for the same company in order that the valve would shut off tight to ANSI Class VI.

With the rand depreciating daily, the cost of these big valves is escalating and re-engineering existing valves is becoming increasingly attractive. With Mitech's local manufacturing knowledge and experience, customers can be confident of quick service - and in many cases receive a valve that will perform better than it did when originally supplied.

With its export drive now firmly established for new valves Mitech is looking at the retrofit market in Australia and England and is busy quoting for refurbishing large high-pressure pump test valves. Customers who think they can benefit by becoming part of this programme can contact their local Mitech office for a free proposal.

Mitech

(011) 462 2160

[email protected]

www.mitech.co.za

Further reading:

Compact valve position indicator
Emerson Automation Solutions Valves, Actuators & Pump Control
Emerson’s new TopWorx DVR Switchbox is an entry-level addition to the DV Series of valve position indicators. It combines a durable resin enclosure, compact size, and a patented cam design that provides a reliable valve position feedback for water and wastewater systems, food and beverage production lines, and industrial utilities.

Read more...

---

Dependable pumping for dewatering in hard rock mining areas
Valves, Actuators & Pump Control
Becker Mining’s Pumpor Vertical Spindle (PVS) pumps are hard at work on many mines throughout Africa, with many units installed recently in the Carletonville area, West of Johannesburg.

Read more...

---

Efficient, affordable solution for electrohydraulic pumps
Parker Hannifin - Sales Company South Africa Valves, Actuators & Pump Control
In the world of construction a revolution is changing the status quo, the electrification of small and efficient construction machinery.

Read more...

---

Redefining Industrial Automation with the new Festo Valve Terminal
Festo South Africa Valves, Actuators & Pump Control
Festo recently introduced its latest innovation in the form of the Valve Terminal VTUX. This invention marks the beginning of a new era in valve terminals, with its features making it an impressive solution for the future.

Read more...

---

New pilot-operated relief valve
Emerson Automation Solutions Valves, Actuators & Pump Control
Emerson has introduced a pilot-operated relief valve for installation on pressurised bullet tanks used to store liquid propane and anhydrous ammonia. This type of pressure relief valve is typically installed on tanks fabricated by OEMs for end users, engineering firms, or contractor customers.

Read more...

---

Pulse valves for dust collection
Emerson Automation Solutions Valves, Actuators & Pump Control
In process manufacturing, especially hard mineral mining, dust particles are unavoidable. If this pervasive dust is not effectively removed, it can accumulate throughout mines, plants and other facilities, becoming hazardous to workers and equipment.

Read more...

---

Case History 191: The weakest link.
Michael Brown Control Engineering Valves, Actuators & Pump Control
Which is the weakest link in a control loop? The answer, without any doubt is that, in most cases, the final control element is the weakest link.

Read more...

---

High-flow solenoid valve
Emerson Automation Solutions Valves, Actuators & Pump Control
Emerson has introduced the new ASCO Series 327C solenoid valve, which features a direct-acting, high-flow design that provides superior flow-to-power ratio. It permits high flows at minimum power levels, making it ideal for use in power plants, refineries, and chemical processing facilities.

Read more...

---

Selection of two-port valves: an open and shut case
SMC Corporation South Africa Valves, Actuators & Pump Control
Little consideration is generally given to two-port valves because they are often perceived as simple devices that only open and close to control downstream fluid supply. Although this is mechanically true, choosing the optimal two-port valve for your application can make a big difference, saving space, weight and energy consumption.

Read more...

---

Emerson software optimises maintenance
Emerson Automation Solutions Valves, Actuators & Pump Control
Emerson has announced the Plantweb Insight Valve Health Application, a powerful software tool that combines Fisher control valve expertise with advanced analytic algorithms. The new app makes it possible for users to visualise an entire connected fleet of valves, while prioritising actions based on the health index of each valve.

Read more...

---