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Tighten the Lock Nut — Adjust Pressure Bolt

Beginner90 mins

Part of project

How to Adjust a Water Pressure Reducing Valve (PRV) · Step 3 of 7

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In this video

After you have adjusted the pressure to your desired level, you must re-tighten the lock nut. Hold the adjustment bolt in place with one wrench while you use another wrench or pliers to turn the lock nut clockwise until it is snug. This will prevent the pressure setting from changing over time.

Goal: Secure the pressure setting

  • Don't over-tighten the lock nut, just make it snug enough to hold the adjustment bolt in place.

Used in this video

  • Wrench (Tool Type: Hand Tools, Power Source: Manual)To tighten the lock nut.
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FAQs

What kind of pressure gauge do I need for this project, and why can't I just guess?

You need a specific water pressure test gauge, like the Watts DP IWTG or Orbit 91130, which connects directly to a hose bib. These gauges provide accurate PSI readings essential for setting your water pressure precisely between 50-60 PSI. Guessing can lead to incorrect pressure, potentially damaging appliances or fixtures.

Is it safe to adjust the PRV myself, or should I call a plumber?

Adjusting a PRV is considered a beginner-level DIY task and is generally safe if you follow instructions carefully. Ensure you have the proper tools and make small, incremental adjustments while re-testing the pressure frequently. If you encounter leaks, stripped parts, or persistent issues, then consulting a professional plumber is advisable.

What's the biggest mistake a beginner might make when adjusting their PRV?

The most common mistake is making large adjustments to the pressure bolt without re-testing the pressure incrementally. This can easily lead to over-pressurization or under-pressurization, requiring more effort to achieve the desired setting. Always turn the adjustment screw in small increments (e.g., quarter-turns) and re-check the gauge after each change.

My water pressure isn't changing even after I've adjusted the PRV. What could be wrong?

If adjustments aren't affecting the pressure, your PRV might be old, faulty, or completely failed and needs replacement. First, double-check that you're turning the correct adjustment bolt and that the locknut is sufficiently loosened. If the valve itself is defective, no amount of adjustment will fix it, and replacement is the next step.

Tighten the Lock Nut — How to Adjust a Water Pressure Reducing Valve (PRV) (Step 3, Video 1) | Stesso