07302016Sat
Last updateFri, 29 Jul 2016 2pm

i

Basics of Elastomeric Seal Design

Basics of Elastomeric Seal Design

Engineers need critical design informati...

Wastewater Treatment

Wastewater Treatment

Society’s desire for a clean envir...

Controlling Our Water Systems, Part II

Controlling Our Water Systems, Part II

To better understand the actuators and c...

Controlling Our Water Systems

Controlling Our Water Systems

Actuators and controls are a critical pr...

The Weekly Report

New Products

  • ja-news-2
  • ja-news-3

Industry Headlines

Advertisement
i

Industry Headlines

Pentair Reports Second Quarter 2016 Results

1 DAY AGO

Pentair plc announced second quarter 2016 sales of $1.7B. Sales were up 4% compared to sales for the same period last year. Excluding the unfavorable impact of currency translation and the positive contribution from acquisitions, core sales declined 3% in the second quarter . Second quarter 2016 earni...

Readmore

ValvTechnologies Names Bryant Holt Industry Director, Fossil Power

2 DAYS AGO
ValvTechnologies Names Bryant Holt Industry Director, Fossil Power

ValvTechnologies, Inc. has appointed Bryant Holt as industry director for the company’s fossil power division. Holt will succeed George Stover, who has served in this role since 2014.

Based in Houston, Holt will have global management responsibility for ValvTechnologies’ fossil power group ...

Readmore

ExxonMobil Expanding Beaumont, TX Facility

1 DAY AGO

ExxonMobil has plans to increase production of ultra-low sulfur fuels at its Beaumont, TX refinery by approximately 40,000 barrels per day, representing an investment of approximately $450 million.

Construction is scheduled during the second half of 2016 to install a selective cat naphtha hydrofining u...

Readmore

LNG’s Surge from Decade-Low Seen Fizzling as Supply Ramps Up

2 DAYS AGO

“LNG’s surge is running out of gas. Liquefied natural gas in Asia, which was in such over-supply that prices in Japan fell to a decade-low in April, has risen by almost half in the past three months as production outages stifled supply, demand rose in places like China and India and a co...

Readmore

Second Quarter GDP Grew Only 1.2% in Second Quarter

23 HOURS AGO

Real GDP in the U.S. increased at an annual rate of 1.2% in the second quarter of 2016, according to the advance estimate released by the U.S. Department of Commerce. In the first quarter, real GDP increased 0.8%.

The increase in real GDP in the second quarter reflected positive contributions from cons...

Readmore

U.S. Durable Goods Orders Down 4% in June

2 DAYS AGO

New orders for manufactured durable goods in June decreased $9.3 billion or 4.0% to $219.8 billion, the U.S. Department of Commerce announced. This decrease , down two consecutive months, followed a 2.8% May decrease. Excluding transportation, new orders decreased 0.5%. Excluding defense, new orders d...

Readmore

Nickel-Copper Alloys

materials_q_and_a_graphicQ: Are the nickel-copper alloys (such as UNS N04400) acceptable for use in accordance with the NACE sour service standards?

 

A: This question has been asked frequently, usually in relation to a valve for an upstream hydrocarbon application involving sour water that also contains chlorides. Nickel-copper alloys can be an economical option for such applications. However, changes in the NACE standards within the last decade have complicated the issue.

The original version of NACE MR0175 released in 1975 allowed N04400 material with a 35 HRC maximum hardness requirement. In 1982, N04405, the higher-sulfur, free-machining version of N04400, was balloted, approved and added by addendum. M35-1 and M35-2, two cast “equivalents” of N04400, were balloted and added to a 1991 revision.

In addition to weak grades, the ­precipitation-hardenable N05500 was also included in the original 1975 ­version, with a maximum hardness of 35 HRC provided the material was hot-worked and age-hardened, solution-annealed, or solution-annealed and age-hardened.

When the MR0175 rewrite was under production as a precursor to ISO 15156, the weak grades (N04400, N04405, M35-1 and M35-2) were omitted for general usage and relegated to specific oil and gas field applications (i.e., they were no longer allowed for valve components). Many end users felt this alloy family was not needed for general sour upstream petroleum applications.

In addition, because of some field failures in N05500 fasteners, an effort was made to eliminate this material as well. In the end, N05500 was retained in the new standard, but was relegated to use in:

  • Wellhead and Christmas tree components other than bodies or bonnets, with specific pH and hydrogen sulfide partial pressure restrictions
  • Non-pressure-containing internal components in valves, pressure regulators or level controllers, and
  • The same specific oil and gas field applications as soft alloys.

Because NACE defines valve shafts and stems as pressure-containing components, this material could no longer be used for shafts and stems when compliance with MR0175 was required.

Shortly after NACE MR0175-2003 was released, it was converted to ISO 15156, which NACE then adopted back as NACE MR0175/ISO 15156. No changes were made regarding the ­nickel-copper materials.

In the meantime, NACE MR0103, the downstream (oil refining) sour service standard, was released (in 2003), and included N04400, N04405, M35-1, M35-2 and M30C (another N04400 cast equivalent), as well as N05500 with the same metallurgical requirements that were specified in the pre-2003 versions of NACE MR0175. No restrictions regarding the types of components that could be made from the N05500 grade were made.

In 2005, ISO 15156-3:2003 Technical Corrigendum 2 (essentially an addendum to NACE MR0175/ISO 15156) was released, allowing use of N04400 and N04405 for general purposes. However, the cast grades were not included in this change.

When NACE MR0175/ISO 15156 Second Edition was published in 2009, N04400 and N04405 were inserted into the main document along with the other solid solution nickel alloys.

A summary of the acceptability of these various nickel-copper materials is shown in Table 1.

vmfall12_repair_table1

The ramification of this situation is that it is not possible to produce many valve designs using an all nickel-copper construction in accordance with the current version of NACE MR0175. If the body style requires a casting (such as a globe valve), the cast alloys are not permitted. In addition, N04400 and N04405 are rarely strong enough to use for shafts or stems, and N05500 is not allowed for those components.

Therefore, unless the valve body can be produced from a wrought material form such as a plate or forging, and the shaft can be made from the lower-strength N04400 or N04405, some other, non-nickel-copper material will need to be used for the body and the stem or shaft.


Don Bush is a principal materials engineer at Emerson Process Management–Fisher Valve ­Division (www.emersonprocess.com). Reach him at This email address is being protected from spambots. You need JavaScript enabled to view it..

  • Latest Post

  • Popular

  • Links

  • Events

Advertisement

Looking for a career in the Valve Industry?

ValveCareers Horiz

To learn more, watch the videos below or visit ValveCareers.com a special initiative of the Valve Manufacturers Association