Can you believe we are reaching Q4 already? To prepare for Knox's annual plant shut down for maintance (Mid December),


Any orders placed after this date will likely be unable to be fulfilled until 2023.

If you have further questions please email or give us a call at 720-710-5669.

Thanks, The Sentry Tech Team

Knox FDC Locks

Calculated at Checkout
  • Model 3110- Knox FDC Lock, 2.5-inch, 3.068 X 7.5 TPI
  • 3111- Knox FDC Lock with Swivel-Guard, 2.5-inch, 3.068  X 7.5 TPI
  • Model 3190- Knox FDC Lock, 1.5 inch, 1.990 X 9.0 TPI
MSRP: $547.00
— You save $155.00
Frequently bought together:


  • Benefits
  • Options
  • Specs
  • Operating
  • Need Help?
  • FAQ


Fire Department Connections (FDCs) are your building's lifeline to fire prevention. When FDCs are left unsecured, they are vulnerable to damage, debris, and vandalism which can constrict the flow of water to fire protection systems such as fire sprinklers and standpipes. Knox FDC Locks protect FDCs by keeping pipes clean of debris. Locks are available in 1.5" and 2.5" configurations and is operated with a Knox Keywrench controlled by the Fire Department.


  • Locking mechanism secures and protects FDCs
  • Stainless steel construction to withstand all weather conditions
  • Available in 1.5" and 2.5"NH sizes
  • Authorized by 2018 IFC1 and IBC2 (Chapter 912.4.1) and 2018 NFPA 13 (Chapter 13.1.13)
  • Enacted in 2003, 2006, 2009 and 2012 (Chapter 912.3.1) and 2015 (Chapter 912.4.1) of IFC editions
  • Enacted in 20016, 2009, and 2012 (Chapter 912.3.1) and 2015 (Chapter 912.4.1) of IBC editions
  • Enacted in 2009, 2012, and 2015 (Chapter 13.1.12)


  • Ensures ready and reliable connections to fire sprinkler systems
  • FDC Swivel-Gaurd brings added protection against vandalism
  • Protects check valves from freezing in cold climate areas
  • Eliminates costly services to back flush the pipes due to debris

Right click HERE to download spec sheet on FDC Locks

Right click HERE to download operating instructions

Right click HERE for more information on FDC Requirements for Colorado



1. Select size:

  • 1.5- Inch NH size
  • 2.5- Inch NH size

2. Swivel Gaurd Protection

In recent years, communities have seen an increase in stolen copper and brass including siamese brass FDC swivel connections. A stolen FDC connection places a building, its occupants and responders at risk. To combat the theft of FDC swivel connections, Knox has developed the Knox FDC Lock with Swivel-Guard™ that covers the entire swivel connection and minimizes the potential of the connection being stolen. With Swivel-Guard™, the set screw is inaccessible making it difficult to remove the brass connection



To insure procurement and delivery of the KnoxVault 4400, it
is suggested that following specification paragraph is used:

Sizes: 1.5-inch and 2.5-inch

Construction and Finish: Stainless steel

Exterior Dimensions: Surface Mount - 7”H x 7”W x 5”D
Recessed Mount Flange - 9 1/2”H x 9-1 /2”W

Lock: Locks with a proprietary Knox Keywrench

Finish: Knox-Coat® proprietary finishing process

Color: Black, Dark Bronze or Aluminum

P/N: P/N: 1.5-inch - 3050; 2.5-inch with Swivel-Guard- 3041; 2.5-inch -3043; (mfr’s cat. ID)


Right click HERE to download complete Spec Sheet

Right click HERE to download operating instructions


Need help finding the right product? Happy to help!

Contact US!

Ordering Support:

Call Us: 720-710-KNOX (5669)

Email Us:

Or simply right click HERE to send us a message!


6311 Washington St.
Unit H
Denver, CO 80216

MON-FRI 9:00AM-5:00 PM MST

We are happy to help with any questions that you may have.

What Product Model Do I Need to Order?

Contact your local Fire or Public Safety Department for Knox product recommendations.

What are Spec Sheets?

Spec sheets are available on this page under the "Brochures & Specs" section or can be found here

Where do I Install the Knox FDC Lock and Storz Caps?

Knox locking FDC caps protect fire department connections and are generally found on the exterior of buildings. Knox Storz Lock caps protect fire hydrant and fire department connections which can be found in stairwells, parking garages and the exterior of buildings.

Who Installs the Products?

After receiving your Knox locking FDC caps, call your responding Fire Department to schedule an inspection and help install and lock the caps.

Have More Questions?

Click here to email us your questions. Or give us a call 720-710-KNOX (5669)

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