Direct Maintenance Services
Rotary Valve
&
Airlock Repair
24/7 Emergency
Free Pickup
Zero Leaks Guaranteed
Airlock leaking? Material bridging? Rotor jammed?
One call to D.M.S. - 24/7 emergency fleet dispatched anywhere in the USA. Free insured pickup. Live expert response in minutes.
(832) 860-5493
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Rotary Airlock Valve Repair & Rebuild
D.M.S. is the nationwide leader in rotary airlock valve repair and full rebuilds - from 6" to 36"+, cast iron to stainless, abrasive-duty to FDA food-grade. We eliminate leaks, restore perfect clearances, and upgrade with hard chrome, tungsten carbide, ceramic coatings, and our famous outboard bearing retrofits - routinely delivering 5-10x longer life than new OEM valves.
Detailed 15-Step Airlock Rebuild Process
Comprehensive 9-Step Airlock Rebuild Process
1. Free Nationwide Pickup
Zero-cost insured transport
2. Teardown & Inspection
Digital report & CMM checks
3. Cleaning & NDT
Glass-bead & crack detection
4. CNC Resurfacing
Restore bore & clearances
5. Advanced Coatings
Hard chrome & tungsten options
6. Bearing Retrofit
Outboard bearing installations
7. Shaft & Seals
Air-purged seals & shaft truing
8. Precision Assembly
Set perfect end & radial gaps
9. Final Leak Testing
100% seal verified & delivered
Top 18 Airlock Failure Modes We Fix
Top 9 Airlock Failure Modes We Fix
Rotor Contact
Signs: Grinding. Fix: CNC + Chrome.
Bearing & Seals
Signs: Leaks, heat. Fix: Outboard retrofits.
Housing Wear
Signs: Blow-by. Fix: Metal spray + CNC.
Material Bridging
Signs: Jamming. Fix: PTFE non-stick coating.
Drive Failure
Signs: No spin. Fix: Motor/Gearbox overhaul.
Shaft Damage
Signs: Vibration. Fix: Shaft truing or replace.
Corrosion
Signs: Pitting. Fix: SS overlay or Halar.
Loose Tips
Signs: Rattling. Fix: Tip weld & replacement.
Pressure Locks
Signs: Low flow. Fix: Vent geometry redesign.
Coating & Material Upgrade Matrix
Top 3 Airlock Coatings
Hard Chrome
Standard duty. 3-5x longer wear life.
Tungsten Carbide
Extreme abrasion. Ideal for fly ash & cement.
Nickel + PTFE
Non-stick. Prevents sticky polymer bridging.
40+ Rotary Airlock Brands We Service
Industries We Serve
Industries We Serve
Cement & Minerals
Abrasive handling, kiln feed, fly ash.
Food & Pharma
FDA compliant & clean-in-place valves.
Chemical & Plastics
Corrosive media & polymer conveying.
Power Generation
Coal handling & extreme temp systems.
Outboard Bearing Retrofit Program
Why Outboard?
- Eliminates 90% of bearing failures
- No product contamination
- Easy maintenance access
- 5-10x longer life
Available For
- Smoot, Prater, Meyer, ACS, Rotolok
- 6" through 36"+ sizes
- Drop-in replacement kits
Included
- New shaft & bearings
- Custom machined adapters
- Air-purged seals
Quick-Clean & Sanitary Options
Rail-Mount Rotor
- Tool-free removal in minutes
- Ideal for frequent cleaning
Polished Food-Grade
- Ra < 15 finish
- FDA & USDA compliant
Venturi Vent Design
- Prevents pressure lock
- Improves flow
In-House Capabilities
CNC Machining
- Housing bore reclamation
- Rotor tip rebuilding
- Custom shaft manufacturing
Coating Facility
- Hard chrome plating tank
- HVOF tungsten spray
- Ceramic plasma coating
Dynamic Balancing & Testing
- G2.5 balancing up to 48"
- 100% seal verification
- Pressure & vacuum testing
Unmatched 12-36 Month Install Warranty
Every D.M.S. rotary airlock rebuild includes a 12-36 month warranty from date of installation - the longest, strongest coverage in the industry.
Rotary Airlock Troubleshooting & FAQs
How do I stop material from leaking out of my rotary airlock shaft seals?
Material leakage along the shaft is typically caused by worn packing or failed labyrinth seals. We resolve this by converting standard packing glands to air-purged shaft seals. By introducing a continuous stream of regulated compressed air into the seal chamber, we create a positive pressure boundary that prevents abrasive product from escaping and wearing down the shaft journals.
What is the standard rotor-to-housing clearance tolerance for rotary valves?
For standard ambient applications, we target a precise rotor-to-housing radial and end clearance of .003" to .005" (.079mm to .127mm). For high-temperature or steam-jacketed systems, clearances must be calculated and widened up to .008" to allow for thermal expansion of the rotor, preventing metal-on-metal contact and housing galling.
Can you convert an inboard bearing rotary valve to an outboard bearing setup?
Yes. Inboard bearings place the bearing directly adjacent to the product stream, leading to premature bearing failure when seals leak. Our outboard bearing retrofit program involves machining custom endplate adapters to move the bearings away from the housing, creating a physical air gap. This completely eliminates product contamination and extends bearing life by 5-10x.
One Call Stops Every Leak
Sealed. Silent. Bulletproof.
Ready for a leak-free, 10x longer-life rotary airlock? We also overhaul connected drive systems, including Falk or SEW gearboxes and motor reducers.
(832) 860-5493
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Email: INFO@DIRECTMAINTENANCESERVICES.COM
