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HR Professionals Gather at VMA Workshop

HR Professionals Gather at VMA Workshop

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Valves in a Cement Slurry Line

Valves in a Cement Slurry Line

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Triple Offset Butterfly Valves

Triple Offset Butterfly Valves

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Industry Headlines

Manufacturers Expecting Increased Revenues, Employment Growth In 2017

Friday, 09 December 2016  |  Chris Guy

Economic growth in the U.S. will continue in 2017, say the nation’s purchasing and supply management executives in their December 2016 Semiannua...

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Industry Headlines

Siemens Industry Acquiring Mentor Graphics for $4.5 Billion

1 DAY AGO

Siemens and Mentor Graphics have entered into a merger agreement under which Siemens will acquire Mentor for $37.25 per share in cash, which represents an enterprise value of $4.5 billion. Mentor will then be consolidated into Siemens Industry, according to the Atlanta Business Journal .

Mentor Graphics ...

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GE Oil & Gas Signs Agreement with TAG GmbH

2 DAYS AGO

GE Oil & Gas has signed an agreement with TAG (Trans Austria Gasleitung) GmbH, a pipeline operator with stations across Austria, to install its new Tuning Maintenance Software (TUMAS) across TAG’s fleet of 16 PGT25 gas turbines. This is the first time this solution has been rolled out across...

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‘Buy America’ Debate Holds Up Water Infrastructure Bill

21 HOURS AGO

A debate in Congress is taking place over whether to restore a ‘Buy America’ provision in the Water Resources Development Act (WRDA) before a final version is voted on. The ‘Buy America’ rule already passed in the Senate version of the bill. It was then pulled from the compromi...

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New Pipeline Safety Rule Expands Excess Flow Valve Requirements Again

2 DAYS AGO

In October, 2016, The Pipeline and Hazardous Materials Safety Administration (PHMSA) announced a final rule that expands safety requirements for excess flow valves (EFVs) to multi-residential and commercial applications. That version of the rule covered the installation of EFVs in new or replaced se...

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Manufacturers Expecting Increased Revenues, Employment Growth In 2017

-1 DAYS AGO

Economic growth in the U.S. will continue in 2017, say the nation’s purchasing and supply management executives in their December 2016 Semiannual Economic Forecast. Expectations are for a continuation of the economic recovery that began in mid-2009, as indicated in the monthly ISM Report on Bu...

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Poll: U.S. Economy to Grow 2.2% in 2017

1 DAY AGO

National Association for Business Economics’ (NABE) December 2016 Outlook Survey forecasts 2.2% growth in real GDP for 2017. The annualized growth rate forecasted for 2017 inched downward to 2.2% in the current survey from 2.3% in September. Both projections illustrate the panel’s expectat...

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Check Valves: Repair or Replace?

In today’s environment of shorter outage windows and shrinking maintenance budgets, the maintenance team should explore all available options when faced with a decision to repair or replace a valve.

As an example, let’s consider the choices when a damaged seat is discovered in a large bore, high-pressure swing check and/or reverse current valve in a typical steam system. Due to the difficulty in making a successful seat repair on this type of valve, the traditional approach has been to “limp” along until a replacement valve is available and an extended outage window is planned to allow the project.

 

The valve replacement approach is typically very costly because:

  • the new valve is expensive and usually has a long lead time
  • removal of the existing valve and installation labor and equipment is costly
  • the replacement process usually requires civil engineering to establish a rigging plan, restraint system and overall safe removal of existing valve and installation of the new one
  • the replacement process will more than likely require quality control management of extensive nondestructive examination and pre/post-weld heat treatment.

An Alternative
Most check valves are designed with a welded, integral seat located in a narrow valve throat and typically set at a 30-degree angle. This design makes repair of the seating surface virtually impossible using “off the shelf” machines and tooling. The lack of equipment to adequately make this repair has in the past left the end-user with one option to restore the integrity of the system—valve removal and replacement.

To remove and replace check valve seats reliably and in a cost-effective manner, the valve repair vendor must utilize custom tooling, procedures and techniques.

Utilizing this special tooling, craft personnel have performed numerous successful seat replacements on check valves, ranging in size from 12-inch NPS to 50-inch NPS. In this repair process personnel typically:

  • document “as-found” condition and dimensions
  • perform liquid penetrant testing (LPT) of the existing seating surface
  • machine-remove the existing alloy 21 hardfacing
  • perform LPT of the base metal (valve body)
  • perform base metal repairs if needed
  • install new alloy 21 hardfacing
  • machine a new seating surface to OEM specifications
  • perform liquid penetrant testing of the new seating surface
  • re-assemble the valve and “blue check” the seating surface to ensure 100% contact
  • document the “as repaired” critical valve dimensions.

These new techniques, along with the traditional valve repair procedures, provide the end-user with a refurbished component, restored to OEM specifications, in this critical application—without the time and expense required for a full valve replacement.

As with all mechanical components, routine maintenance and inspection is critical to keeping these types of valves in proper working order. Most end-users follow a carefully planned maintenance schedule; however, it is worthwhile to recap the elements of a successful program:

  • Schedule routine inspection and documentation of valve condition.
  • Perform non-destructive examination of valve seating surfaces and base metal pressure-containing components.
  • Maintain seating surface condition through a repair process such as the one described in this article.
  • Refurbish or replace worn valve components discovered during the inspection process.

If replacement of these types of valves does become necessary, contact an OEM to assist in the selection of the best valve for the application; make allowances for rigging and restraining the existing piping prior to valve removal; and take the opportunity to make any configuration changes needed to improve valve maintenance accessibility.

TY L. POTTER is Vice President of Operations, Southeast Valve, Inc.  located in Charlotte, NC. Reach the author at 704.588.0973.

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