Maintenance & Reliability

Improve welding technology for heavy-wall pressure vessels in creep-resistant steel

The standard practice recommended for high-pressure vessels with heavy wall thickness requires the implementation of weld joint preparation with a narrow gap technique. This generally calls for a two-beads-per-layer sequence, along with the use of the submerged arc welding (SAW) process.

Reliability: Include pump wear rings in your upgrade efforts

Bloch, Heinz P., Hydrocarbon Processing Staff

Most centrifugal pump designs include replaceable rotating wear rings on the impeller (impeller wear rings) and stationary wear rings inside the casing (case wear rings). Although pump wear rings are simple components, they can have profound impacts on pump reliability, efficiency and safety. These wear rings serve three purposes:

Editorial Comment: It’s all in the makeup of things

Nichols, Lee, Hydrocarbon Processing Staff

This issue of Hydrocarbon Processing features a topic that has been addressed in sections of the magazine for several decades, but has never been a focal point of the publication. That topic is materials manufacturing.

Use your data to its full potential to prevent outages

Creef, B., HIMA Americas, Inc.

In a process plant, the safety system is responsible for the protection of personnel, resources and the environment, by taking the plant to a safe state in the event of a fault. However, is the system capable of contributing more to the plant’s uptime and profitability?

Evaluate structural stiffness for piping stress analysis

Choudhury, M. G., Tripathi, R., Reliance Engineering Group (REG)

Hydrocarbon plants use a system of pipes of various sizes, pressures and temperatures. Sometimes these pipes have pulsating flows that result in piping system vibration. These piping systems must be designed for a high degree of reliability, which requires a comprehensive piping stress analysis for thermal, sustained, occasional and dynamic loading conditions.

Consider pitot tube pumps for low-flow, high-head applications

Alshaye, A., Saudi Aramco

Low-flow, high-head pumping requirements in refining and petrochemical plants make up less than 2% of the total pump population. This minor percentage is creating significant reliability concerns, which result in low mean-time between failures (MTBF), as well as high maintenance costs.

Eliminate mechanical seal failure in a crude distillation unit

Telmesani, A. A., Yanbu Aramco Sinopec Refining Company (YASREF) Ltd.

Multiple mechanical seal failures in a crude distillation unit (CDU) resulted in total losses of $3 MM in a refinery since its startup in January 2015. The maximum seal life achieved did not exceed 6 mos, which was much shorter than the American Petroleum Institute (API) 682 “Advancements in Mechanical Sealing” goal of 3 yr of seal life.

Japan plans maintenance at seven naphtha crackers in 2018

TOKYO (Reuters) — Seven naphtha crackers in Japan are expected to be shut in 2018 for scheduled maintenance, industry and company sources said.

Engineering Case Histories—Case 99: Pooling knowledge and experience builds personal and team success

Sofronas, A., Consulting Engineer

With the help of an excellent mentor, I became adept at analyzing equipment and structures at the start of my career, using analytical techniques.

Reliability: Dry gas sealing technology replaces segmented carbon rings in small steam turbines

Bloch, Heinz P., Hydrocarbon Processing Staff

Since the late 1800s, small steam turbines have incorporated bushing-type, single-piece and/or segmented carbon gland components to reduce and prevent steam leakage along the shaft.