You work in a Northern California refinery that’s been around a long time. Locals will tell you it’s always been there. Maintaining an aging refinery has its challenges. In addition to management that expects you to maintain equipment as efficiently and cost-effectively as possible, you have regulatory agencies (virtually) looking over your shoulder. You need to be compliant with the current health, safety, and environmental regulations. Your HSE department should be guiding you in understanding Cal/OSHA and BAAQMD requirements. 

Among the thousands of pieces of rotating equipment in your refinery, centrifugal pumps constitute a significant number. Many of them may have been operating for decades. With the majority of pumps processing some variant of potentially hazardous hydrocarbons, often at high pressure and high temperature, maintaining the reliability of rotating equipment goes hand in hand with meeting rotating equipment HSE.

Rotating Equipment HSE: Focus On Leakage

A centrifugal pump is a relatively simple apparatus with essentially one moving part—an impeller driven by a motor (a rotating equipment category deserving of a series of separate blogs regarding HSE compliance). Considering the hazardous nature of hydrocarbons processed in refineries, leakage around the impeller shaft is the most significant HSE concern for any centrifugal pump. 

A pump “leak” covers a lot of different scenarios. A leak could be fugitive emissions detectable only with a gas detector, a visibly obvious trickle that indicates seal failure, or a deepening puddle that demands immediate shutdown. Leaks can release toxic (hydrogen sulfide) fumes, damage impeller shafts or motor bearings, create an explosive vapor cloud, or cause a fire. 

I’ve found that you can prevent centrifugal pump leakage that could expose you to HSE compliance sanctions by focusing on three areas: inspection practices, mechanical seals, and seal support systems. Let me explain why focusing specifically on these three areas can help you avoid leaks and stay compliant.

Scheduled, Proactive Inspection Practices:

With hundreds of centrifugal pumps in an aging refinery, consistent inspection schedules and practices are vital to maintaining pump reliability. Proactive, scheduled maintenance anticipates and prevents potential problems from developing. Early detection of developing problems prevents small leaks from becoming catastrophic. 

• Do you have an inspection schedule for centrifugal pumps and seal support systems? 
• Does the schedule align with pump criticality and usage, e.g., condition-based, time-based, or calendar-based?
• Does your enterprise asset management system track inspections and reports, or alert to inspections that have been missed?
• Are pumps easily accessible for inspections and maintenance or do location and surrounding infrastructure make it difficult for maintenance personnel to efficiently and safely access and work in the area? (Note: Seal support systems can be properly remoted to allow access or not clutter the existing area.)

I’ve found that centrifugal pumps in aging refineries are often encumbered by infrastructure that has gradually “grown up around them” since they were first installed. Over the years, maintenance personnel have become inured to these complications. In some cases, poor accessibility may present an HSE concern that requires a redesign. Accessibility, based on inherently safer design guidelines plays an important role in helping maintain rotating equipment HSE compliance. 

Do Mechanical Seals Meet Current Pumping Requirements?

Mechanical seals are essential in meeting rotating equipment HSE requirements by preventing hydrocarbon leakage from centrifugal pumps. In aging refineries that have gone through changes in the types of hydrocarbons being processed and the processing conditions (moving from sweet to sour crude) you’ll likely find pumps using mechanical seals that no longer meet the processing requirements. The seals may not yet have failed or leakage is imperceptible, but you’re operating on a thin edge of reliability. To avoid these potential problems, ask yourself: 

Equally important are the mechanical seal support systems that help ensure mechanical seal reliability and prevent leakage. A change in process fluids or conditions that merits a change in mechanical seals almost always involves a change or modification of the mechanical seal support system.

Seal Support Components and Systems Are Critical to Mechanical Seal Reliability 

While mechanical seals are the first line of defense against pump leakage, those seals depend on seal support systems that are properly designed and configured to your specific pumping requirements. It doesn’t always take a major change to a seal support system to boost mechanical seal reliability. The addition of a heat exchanger could be just what’s needed to compensate for increased process fluid temperature. A pressure gauge can provide immediate confirmation that barrier gas is being delivered to a dual seal at the right pressure to prevent leakage. Replacing a strainer with a cyclone separator can more effectively filter particulates and contaminants that foul seal faces, leading to seal failure and leakage.

For some of your aging pumps, the better approach is a complete replacement of an outdated seal support system. Optimum tubing geometry, bypass loops, instrumentation, and ergonomically-designed panels facilitate safe, easy inspection and maintenance activities. When you have hundreds of pumps, design features that help maintenance personnel confidently and accurately monitor seal system performance can significantly reduce the chances of pump failure and help ensure rotating equipment HSE compliance.

Local Expertise to Help With Rotating Equipment HSE Compliance

Bay area refineries can take advantage of an experienced, local seal support system partner—such as Swagelok—who has been helping refineries comply with rotating equipment HSE requirements specific to centrifugal pumps. Swagelok well understands the demands made on Northern California refineries by Cal/OSHA and BAAQMD, and offers comprehensive services and products to help you meet rotating equipment HSE compliance goals. Our Field Engineers confer with you on-site to assess your specific needs, taking into account factors that could risk HSE non-compliance. 

Based on the Field Engineer’s assessment, you’ll receive a list of recommended component upgrades to safely meet current processing requirements. If a system replacement is needed, you’ll receive detailed design and technical documentation for review and approval. After you’ve approved the recommendations and designs Swagelok’s certified technicians will fabricate your seal support systems following ISO 9001 standards. Our multi-million dollar inventory of the highest-quality materials and components reduces fabrication and delivery time. 

As part of our ISO 9001 process, we thoroughly test your seal support system prior to delivery. Whether it’s the relatively simple API Plan 12 - Flush with Strainer or the more elaborate API Plan 52 - Buffer Fluid Seal Pot, you’re assured of the finest quality components and assembly process. And to give you added confidence in working with Swagelok, our seal support systems come with the industry’s strongest Lifetime Warranty.

To find out more about how Swagelok Northern California can help you meet rotating equipment HSE compliance requirements with seal support system solutions specifically configured to your process needs, contact our team today by calling 510-933-6200.

About Paul Lesnau | Sales Manager, Business Development Manager, and Field Engineer

Paul holds a B.S. in Mechanical Engineering from North Dakota State University. Before joining Swagelok Northern California, he was the West Coast Regional Sales Manager for an organization focused within the pneumatic and hydraulic industry where he supervised product distribution throughout the western United States, Canada, and Mexico. While in this role, he was able to help provide technical and application-specific expertise to customers and distribution to drive specifications.