Valve Overview

NC Servo Technology provides repair and reconditioning for the MOOG D633-520B. With in-house tooling and stocked parts, we keep turnaround times short.

Experience and Warranty

We’ve built our shop around one thing: industrial repair. With decades of hands-on experience and deep product knowledge, we deliver consistent results.

Specializing in MOOG D633-520B servo valve technology for over five decades

Frequently Asked Questions

We confirm next steps with you if a unit can’t be rebuilt. No work proceeds without your approval.

Yes. Every unit goes through diagnostic testing and we provide an assessment before moving forward.

Send the unit in whatever condition it’s in. We clean everything during teardown before inspection begins.

We recommend sending pictures, especially if the model number is unclear or there is visible damage.

We regularly work on units with missing labels. Send us a few images and any visible part numbers, and we can usually match it.

How We Rebuild This Valve

We rebuild every valve from the inside out: cleaning, inspection, parts replacement, reassembly, and bench testing.

  • Final Performance Verification: After reassembly, each valve undergoes bench-testing against published performance specs.
  • Cleaning: Units go through a mineral bath, with ultrasonic cleaning used for delicate internals.
  • Leak and Pressure Testing: The reassembled unit is leak-tested and pressure-tested to verify it meets published specs.
  • Complete Disassembly: The unit is disassembled and all parts are laid out for individual inspection.

Hydraulic Testing Process

NC Servo Technology operates over a dozen dedicated flow test stands, including setups for proportional and servo valves. Every valve goes through performance and leak testing using industry-standard fluids including MIL-5606 and Skydrol. Our functional testing verifies consistent performance.

Common Applications

Our professional repair services for the MOOG D633-520B are trusted across various sectors including Manufacturing, Aerospace, and Plastics & Injection Molding. We understand the unique demands of valves in these environments.

MOOG D633-520B Specifications

Every MOOG D633-520B we service is tested under operating environments. Our diagnostics verify performance against published specifications. Performance data and Specification sheets are available for purchase upon request.

Technical Information

For detailed insights into your MOOG D633-520B, we can provide access to service logs and reports. This transparency offers you record-keeping and aids in long-term maintenance planning.

Maintenance Tips

  • Keep a spare MOOG D633-520B on hand to minimize downtime during unplanned failures.
  • Schedule preventive maintenance intervals based on duty cycle, not just calendar time.
  • Use only manufacturer-recommended hydraulic fluids to protect internal valve surfaces.

Get an Expert Repair for Your MOOG D633-520B

Request pricing, availability, and turnaround for your MOOG D633-520B. NC Servo Technology provides hands-on repair with a 1-year warranty. Contact us to schedule your repair.

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NC Servo Technology is an independent third-party repair facility. We are not affiliated with, endorsed by, sponsored by, or authorized by MOOG or any original equipment manufacturer (OEM), nor do we claim to be a MOOG service center. All brand names, trademarks, model numbers, and part numbers referenced on this page are the property of their respective owners and are used solely for identification and compatibility purposes.