Showing posts with label valve. Show all posts
Showing posts with label valve. Show all posts

Tuesday, November 15, 2016

Special Application Challenges Call For High Performance Butterfly Valves

high performance butterfly valve double offset with actuator
Series 400 High Performance Butterfly Valve
ABZ Valve
Industrial process control applications can present stringent and challenging performance requirements for the physical equipment and components that comprise the process chain. The valves employed in fluid based operations need to be resistant to the impact of extreme fluid conditions, requiring careful design and selection consideration to assure proper performance and safety levels are maintained in a predictable way.

Industrial valves intended for extreme applications are generally referred to as severe service or high performance valves. While there are plenty of published and accepted standards for industrial valves, one does not exist to precisely define what constitutes a severe service valve.

So, how do you know when to focus valve selection activities on severe service or high performance valves, as opposed to those rated for general purpose? There are a number of basic criteria that might point you in that direction:

  • Extreme media or environmental temperature or pressure
  • High pressure drop operation that may cause cavitation
  • Rapid or extreme changes to inlet pressure
  • Certain types or amounts of solids contained in the fluid
  • Corrosive media

Certainly, any of these criteria might be found in an application serviceable by a general purpose valve, but their presence should be an indicator that a closer assessment of the fluid conditions and commensurate valve requirements is in order. The key element for a process stakeholder is to recognize when conditions are contemplated that can exceed the capabilities of a general purpose valve, leading to premature failure in control performance or catastrophic failure that produces an unsafe condition. Once the possibility of an extreme or challenging condition is identified, a careful analysis of the range of operating conditions will reveal the valve performance requirements.

There are numerous manufacturers of severe service or high performance valves, each with specialized product offerings focusing on a particular performance niche. ABZ Valve manufactures high performance butterfly valves ranging from 2-48 inches and 150-600 psi. The valve design is ideal for manual or automated actuation, installed with a manual hand gear, electric actuator, or a pneumatic actuator. Seats are available as soft, metal, and fire safe, and body types include wafer, double flanged, and butt-welded. Construction materials include carbon steel and 316 stainless steel. A range of options and variants are available to customize the valve build to suit a replacement or new installation.

More information about the ABZ Valve high performance offering is included below. You can always get more information and discuss your special requirements with a valve specialist. They have application experience and access to technical resources that can help with selecting the right valve components to meet your severe service and high performance applications.

Friday, May 27, 2016

Lost Plant Air a Hidden Source for Energy Savings

Save energy costs
Save energy costs by reducing
consumption of plant air.
Industrial plant air is one of the easiest sources of power to transmit and use. It’s also one of the most costly to generate. Information from the United States Department of Energy (DOE) indicates a wide variety of factors determine the cost of compressed air. These include, but are not limited to, local electrical energy cost, efficiencies of electric motors and compressors, load factors, and service time.

Plant maintenance are becoming more aware of air leaks and the subsequent increases in cost to overcome lost power because of those leaks. One of the major culprits for lost air in a plant is the pneumatic control valve positioner and the air required to operate them. In a typical process plant, there could be hundreds of control valves. Each control valve uses a positioner to move the valve actuator, based on a set point signal from a controller.

Control valve with SIPART
Control valve
with Siemens SIPART
It is the control valve positioner where the greatest air consumption savings lies.

Years ago, when electricity was cheap and when valve positioners were first introduced, plant maintenance and engineering were not concerned with something called the “bleed rate” of the positioner. Over the years though, plant personnel lost track of bleed rate and pretty much forgot that a positioner is just part of the system and it operates on air. Today, a modern process facility such as a power plant, refinery, or chemical plant can have several hundred control valves with positioners. The combined air loss due to the positioner “bleed rate” can be significant.

SIPART positioners
Siemens SIPART positioners
An immediate solution to this problem is to replace the control valve positioners with modern, energy-efficient, low-bleed models. One model, the Siemens SIPART PS2 has a proven track record of providing substantial savings to large plants. In one case, a tabacco company that had 2500 positioners was planning on spending $600,000 on a new compressor to increase output. After reviewing the capabilities of the low bleed positioner and running some tests, the plant decided to implement a plan for replacing the positioners which mitigated the need for a new compressor.

The significant change in technology came with the adoption of the adoption of a piezo ceramic valve block in low bleed positioners. Traditional positioners used an I/P and spool valve which both leaked air. Over time the leaks from these two parts is significant.

Could you and your plant be in the situation where lost energy efficiency through leaky positioners is costing big bucks? If you’re even the slightest bit concerned, call in an applications expert now for a system review.