The potential for hose failures is a major source of stress for chemical plant managers. Frequent replacement is costly, but using hoses beyond their time poses safety risks to employees. To determine the proper replacement interval, plant managers and operators must establish a preventive maintenance plan by tracking and logging performance variables.
For example, consider a refinery that has 100 identical hoses in operation, half of which are steam cleaned and half of which are not. Due to the rigors of the steam-cleaning process, the refinery must replace the steam-cleaned hoses annually to ensure safety. However, the hoses that do not get steam-cleaned will last up to five years before they need to be changed out. The refinery maintenance manager may opt to replace all 100 hoses annually simply because half of them must be replaced, and it would be easy to handle them all at the same time.
But given the gap between the required replacement intervals, it would be more cost effective to move the hoses that do not get steam cleaned to a five-year replacement interval. At $200 per hose, this shift could improve the facility’s bottom line by nearly $40,000. In a refinery or processing plant where margins are tight, that’s not an insignificant sum.
7 Keys to an Effective Preventive Maintenance Plan
A solid preventive maintenance plan requires collaboration with a reliable supplier. The supplier should be able to outline the general inspection and replacement guidelines for a plant’s specific type of hoses. The next step is to observe the hoses regularly and record the findings.
1. Identify all hoses in the plant
Before deciding on replacement intervals, it’s critical to understand exactly where all the hoses are in the plant. Conducting a complete audit allows operators to identify and tag each hose in the facility (Figure 1). During the audit, record the hose type, part number, process fluid, pressure or temperature ratings, vendor name and vendor contact information.Immediately log the data and supplemental information into a spreadsheet, including the hose size, length, construction and core material. Note any end connections, cover type, reinforcement layers, cleaning procedures, mounting needs, the hose installation date and when the expected replacement date. If the audit process seems overwhelming, consider asking a reputable supplier to conduct the review.
2. Track the lifecycle of each hose
Once the audit is complete, create a regular schedule surrounding hose inspections, using the supplier recommendation as a starting point (Figure 2). Most scheduled inspections are strictly visual, seeking to find signs of wear, such as kinks, cuts, general deterioration, corrosion or scrapes. Fortunately, these routine inspections can alert operators to hoses that must be replaced before catastrophic failures and rarely require system downtime. During these inspections, record the observations in the master spreadsheet, including the service interval. Keeping such historical information for each hose can inform future purchasing decisions.Also, closely observe and record hose-failure details, including the severity, location and the mounting of the hose. Paying attention to these details will allow an appropriate post-mortem and future action plan to ensure such a failure does not happen again.
3. Determine whether you need a protective cover
Sometimes, a protective cover may be necessary to keep the hose in working order. To protect hoses from weld spatter and the deleterious effects of UV light, operators may choose to use thermosleeve covers. Adding a cover will not change the technical data specifications for a particular hose. However, when choosing a cover, it’s crucial to understand its intended purpose. For example, to protect a hose against abrasion, a thermosleeve isn’t the appropriate cover. Instead, consider a spiral guard or another similar cover specifically designed to protect against friction.
4. Eliminate Hose Strain
Hose strain is a common problem involved in refinery or processing plant operations. During the regular inspections, observe and record conditions that provide additional strain to the hoses and remove them when practical. Examples of strain include exposure to external heat sources, pulsation, friction with other equipment or obvious design flaws.
Common causes of hose strain include:
5. Follow inspection and replacement protocols
Continue to perform periodic inspections even after establishing a replacement plan. Conditions in refineries and processing plants change rapidly, and established inspections are necessary, along with replacement intervals, to ensure optimal performance.
6. Analyze the data
Regularly analyze data against the established inspection and replacement frequencies. Armed with this analysis, operators can make real-world decisions about whether the intervals effectively serve their purpose. If they’re not, operators can adjust them to account for safety or budgetary concerns. It also may make sense to perform a destructive test to confirm the replacement was necessary.
Also, take note of hose changeouts, and talk to the supplier about alternative designs that could extend hose life. Perform a cost-benefit analysis to make sure the alternative makes financial sense for the plant.
7. Be prepared with spares
Establishing regular replacement intervals allows operators to order replacements well before they are needed. In addition, there are several hose categories in which it makes sense to have spares on hand at the refinery or processing plant, including:
- Hoses for special applications: If a particular hose is in short supply, consider having spare inventory.
- Hoses for critical safety or process applications: Have spare hoses on site that are critical for ensuring safety or plant uptime.
- Hoses that are likely to fail: Hoses that are under severe strain could fail prematurely because of the operating conditions around them. Have extra hoses available at a moment’s notice.
Creating an appropriate preventive maintenance schedule for industrial hoses may require time and money upfront. Still, chemical facilities can expect to easily recoup those costs through less downtime and improved safety.