This question should be moved to the valve section. If you have found metal chips also add type of valve and valve and operational details.

My general answer:

It is not usual to find metal chips directly from valves.

Most metal chips are from maintenance work, opening the pipes and not properly clean before closing. Typical this will give metal from sawing, filing, grinding or welding. (Typical is also that anyone concerned will deny this is the case.)

The fluid itself can also be contaminated.

Valves might also, but seldom, give chips, and not directly depending on valvetype. Most often this is from old valves, not maintained or changed in time, where spindels, clacks or seats or metal sealing get frayed or splintered by to high closing or opening forces, and/or frequent/long use where also inner metal faults may contribute. Sticking fluids and solid particles might be involved.

Depending on process conditions (fluid and operational) the valves might be of wrong type.