The drawing shows an insulated cover or protective enclosure - whatever term you use. The bottom line is that the project plan calls for something to protect the valve or pump system. As a project engineer you probably check with a colleague to see what type has been used in the past. You probably also turn to the internet to learn more about your options.
Your goal at that point is to satisfy the spec. However, there's another perspective worth considering - and one that will live with the consequences, good and/or bad, of your selection for quite some time. That's the perspective of the maintenance team.
In our experience there are 3 general maintenance considerations when selecting valve covers, aluminum pump enclosures, or protection for other equipment. They include:
If PMs are simple, this is reality. Sometimes stuff breaks. When that happens, normally workers need more access than a single panel to let them get to the gauges and filters. Some manufacturers can provide panels that can be ganged together for equipment replacement considerations. In fact, the entire length of one or more sides of an enclosure can sometimes be made of removable access panels. What if a large portion of the fire pump system, water tank, or air compressor needs to be replaced? Repairmen 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. Why not? If you can still economically meet ASSE standard 1060 why wouldn't you design a custom enclosure with access from above into valve and pump covers? This and other specific design considerations are covered in our pump covers checklist.
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. However, 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 2-3 weeks to build. Although it's spread across different budgets, of course, the savings in long term maintenance often dwarfs any customization cost.
Second is the assumption that in order to deliver all this convenience for the maintenance team, valve covers or pump covers will have to be significantly over sized. That is true for some traditional building or shelter styles. A modular industrial enclosure, however, can be designed so that doors and 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 and doors open to allow full and unconstrained maintenance access as required.