Friday, September 27, 2013

Outstanding Service Years After the Sale

Valve before removal
In 1987, RENCOR Controls supplied one of the largest names in paper and packaging products (a pulp & paper plant) a 6" Samson model 3251 globe valve for a power boiler feedwater application.  Boiler feedwater is a critical service. Valve failure can potentially shut down the boiler in the paper mills' power generation facility.

After the initial sale, and since 1987, RENCOR has provided onsite, yearly routine maintenance on the valve. The valve continued in service, without problem, through September 2013.

Wednesday, September 25, 2013

General Intro to Ball Valves

Ball Valves
Variety of ball valve types
Ball valves are grouped by how the valve body is made/assembled. The groups are uni-body, 3-piece, split-body, top-entry, and welded body.

Ball valves are further defined by the machined hole in the ball, called the port.

A full port valve has a port the same size as the pipeline resulting in better flow characteristics. Flow coefficients are much better, but at a higher price. There are many cases where a reduction in diameter, or the resulting change in flow is detrimental.

Thursday, September 19, 2013

Solving a Problem on High Temperature Gas Service

Gas applications many times are thought to be pretty easy applications as long as you get the seat material and wetted part compatibility correct. However, in some cases, these gases can be delivered at very high temperatures, which causes headaches when applying the proper valve.

RENCOR was approached by a customer in China who needed a high cycle, high temperature, fast operating valve. The process gas was 700 deg. F and the process pressure was 272 PSIG.  The customer also required the valve to operate in 0.5 seconds. The biggest challenge was not the temperature itself, but the lack of lubricity. The high temperature gas was very, very dry. All the metal seated ball valves they were testing ended up either galling, or were operating too slowly.

RENCOR teamed up with Velan Valve who engineered a metal seated ball valve rated for 700 deg. F at 272 PSIG. RENCOR designed a custom actuation package that delivered a high volume of high pressure supply air to a rack and pinion actuator that sped operation up to a very fast 30 milliseconds. Problem solved.

Tuesday, September 17, 2013

Samson Controls Introduces Helpful "How-to" Videos

Samson Controls, a leading manufacturer of control valves and regulators in the chemical, petrochemical, pulp and paper, power and HVAC industries is introducing a great page of "how-to" videos.

You can see them at the RENCOR Controls site here. You can also see them on the Samson Controls site here. These videos are intended to answer the most common maintenance questions and new videos will be added regularly.

Thursday, September 12, 2013

RENCOR Uses Innovation and Eye for Design to Reduces Plant Spare Parts Costs

standardized valve brackets
An age old problem at many plants are the countless types of valve and actuator brackets. Many are unique, few are standard. The need for on-hand replacements constantly puts pressure on plant inventories.

Tuesday, September 10, 2013

Paper Mill Saves Big from RENCOR'S Engineering Skills

It was once said that "a paper mill uses everything it produces except the shade the building casts". In this highly competitive business, efficiency and cost-savings go directly to the bottom line.

A well-known New England paper mill had a critical process that required two very large (24") triple offset, metal seated butterfly valves to precisely control flow manually with a gear operator. On top of that, the valves had to be zero-leakage when in the off position. Even with the best known gear operators installed, it was still difficult for the paper mill to get the control they needed.


Thursday, September 5, 2013

Small Process, Big Problem: Sometimes the Solutions are Pretty Simple

Spring return handle ball valve
Spring return ball valve
Problem: Leaks, puddles and spills under the manual valve use for sampling solvents.

Scenario: Customer routinely draws samples of solvent for testing using manual ball valves. Manual valves are not closed tightly by operator, causing small leaks and minor spills. Leaks are not at first noticeable, but drips slowly over time leading to a potentially hazardous situation. Ultimately, its an operator error situation. The fix needs to remove the human from the process.

Tuesday, September 3, 2013

An Alternative to Safety Relief Valves - Safety Trip Stop Valve

Figure 1
The Safety Trip Stop Valve shown in figure 1 is an example of the automated valves supplied by RENCOR Controls as an alternative to Safety Relief Valves as allowed by the Power Piping Code 1987Adenda to the 1986 issue. B31.1 paragraph 122.14.12.

The Power Piping Code allows for the use of this Safety Stop Valve as an alternative to Safety Relief Valves in applications where their use is difficult or impractical. Paragraph 122.14.12 from the Power Piping Code B31.1 reads as follows: