By Craig Carmon, Safe-T-Cover
Spec a pump enclosure once, live with it for years.
Call it an enclosure, hotbox, safety cover, or shelter — whatever term you use, the bottom line is that the project plan calls for something to protect the pump skid, valve station, or other equipment. So as a project engineer you probably check with a colleague to see what type has been used in the past. And you probably turn to the internet to learn more about your options.
Your goal at that point is to satisfy the spec. But there's another perspective worth considering, since those affected will have to live with the consequences, good and/or bad, of your selection for some time. That's the perspective of the maintenance team.
In our experience there are three general maintenance considerations when selecting a pump enclosure or protection for other equipment. They include:
It's simple. The easier it is to do the maintenance, the more likely it's going to be done according to schedule and completely. An enclosure should take into account all PM points (filters, fittings, gauges, drainage cocks, etc.) and ensure that there is ready access to those areas. A great way to do this is to position doors so that the enclosure can be sized to accommodate the equipment (disregarding room to work around it) and yet provide direct maintenance access at those key points.
If PM is simple, this is reality. Sometimes stuff breaks. And when that happens normally you need more access than a panel to let you get to the gauges and filters. In fact, you may well need to reach in from above to hoist components out, and then to lower replacements back in. That means you either have to tear the enclosure apart, or you design that capability in up front. And why not? If you can still economically meet ASSE standard 1060, why wouldn't you design access from above into your pump enclosure?
Temperature extremes can significantly shorten the life span of certain equipment, or lead to immediate failure. Winterization is a common enclosure requirement — and that means a heater, unless you use swaddling blankets for your equipment. But matching the heater to the conditions (wattage, wet environment protection, heating the slab, etc.) often requires a bit more than a casual guess. And the opposite is true as well. Venting excess heat with louvers or fans may keep your enclosure cool enough to prevent damage, but, increasingly, equipment is controlled with sensitive electronics which may have maximum ambient operating temps. So air conditioning your enclosure may make sense too.
Challenge Traditional Assumptions
There are two traditional assumptions that crop up at this point. First, optimizing the pump enclosure to accommodate all these factors means a highly customized and expensive cover with a long lead-time. The highly customized part is right. But it's typically not nearly as costly as engineers assume. You should have pricing and drawings within a couple days of asking, and the enclosure itself shouldn't take more than two to three weeks to build. And although it comes from different budgets, of course, the savings in long-term maintenance often dwarfs any customization cost.
Second, challenge the assumption that in order to deliver all this convenience for the maintenance team, the pump enclosure will have to be significantly over-sized. That is true for some traditional building or shelter styles, but a modular enclosure can be designed so that doors/access panels are placed directly in front of components which require maintenance. That means that with only required operational clearance the enclosure can be sized efficiently, yet panels/doors opened to allow full and unconstrained maintenance access as required.
A custom enclosure might not only economically meet your design drawing requirements, but also enable years of ongoing maintenance to keep everything running well.
Image credit: "Confined space," © 2000 SmartSign, used under an Attribution 2.0 Generic license: http://creativecommons.org/licenses/by/2.0/