Any reason why I can't use a "valve box" as an underground pull box? Doesn't say "electrical" on the lid but is less than half the price of one with exact same dimensions that has "electrical" on the cover.
The "valve box" is for protecting irrigation valves used for landscaping. The valves do have 24V ac solenoids in them. They are at least legal for direct burial rated wire that is low voltage. What is your application?
Other than the word "electrical" and the price, probably no difference. Possibly made on the same equipment line. For irrigation use, the wires are joined with something similar to wire nuts but they have a type of grease packed inside them to resist corrosion. A few problems that may pop up in your application are irrigation valve wiring and their associated connections are only energized for short periods of time - minutes to a couple hours daily or even weekly. DC power thru connectors for an extended period of time are more prone to galvanic corrosion. I don't know if solar cables are rated for direct contact with soil or immersion in water. I have never seen the valve boxes have anything but 24 volt AC wiring in them.
There actually isn't any connections just two ends of underground conduit so I could pull the cabling through one then the other. The wiring is continuous. Just want physical protection and ability to access it in future if need be.