Quiet Latch

The "Quiet Latch Sealing System" (QLSS) by DHSI: 
A 3-part "Program" that ensures the smooth closing, sealing and latching of fire doors

DHSI manufactures patented gasketing and related hardware products that affect the opening, closing, sealing, latching and securing of doors. All DHSI products are designed to perform as a sealing and securing system.

DHSI believes products installed in the field as an opening protective should meet all current code requirements found in IBC, UBC 7-1 and 7-2, NFPA 80, NFPA 101 Life Safety, ADA, STC requirements of the local code (such as Title 24 in California) or by the architect, and so on; but not just as evidenced by a manufacturer in individual tests, but rather as conforming to all the requirements when inspected as a completed system in the field. This is precisely why fire marshals in many states shine a light on the frame and reject any openings that allow light to pass the frame perimeter. Equally important is that DHSI believes installers of life safety products should not have to make field modifications to fire tested components such as die grinding perhaps 1/4" out of a strike plate to allow the door to latch and get the torque on the lever closer to the ADA limit of 15 inch pounds. DHSI believes architectural specifications should reference Field Quality Assurance criteria that verifies conformity. This is a truly innovative systems approach!

Only DHSI products can offer this level of assurance and still maintain an STC of 32 on a 20 minute door. DHSI products can show evidence of conforming to the specifications and field performance criteria even with the "allowable" tolerances of 1/4" warp and 1/16" out of plumb and still have the torque on the lever under 15 inch pounds.

complete 08710 or 08730 Performance Specification is available on diskette, e-mail or by downloading from the DHSI website. Architectural Details are also available on AutoCAD. If the current specifications are e-mailed to DHSI, the recommended changes will be inserted and highlighted for architectural review.


Evidence shall be provided that the STC specified and/or required by local code, as well as any requirements for smoke gasketing can be maintained under industry allowable tolerances for warp (AWI) and plumb (SDI). Evidence shall be provided that the gasketing system can meet this criteria and also maintain the criteria under the Field Quality Assurance Criteria.


This is the missing control factor in the installation process. To ensure and validate the proper closing, latching, sealing and securing of a door the manufacturer of gasketing shall provide a written program of Field Quality Assurance, acceptable to the architect that provides the site superintendent and installers with knowledge as to the industry acceptable standards for tolerances in manufacturing and field installation. DHSI offers the "Industry Standards and Recommended Guidelines For Installation" copyright forms. The program shall create an audit trail of documentation for the inspection of pre-machined doors for machining and sizing, including hinge backset and depth of mortise, width and height. An "Installation Checklist" guideline shall also be furnished for verification of acceptability of related door, frame and hardware components prior to installing gasketing. These forms shall be part of the submittal process and shall be acknowledged by the site supervisor and returned to the manufacturer on a timely basis.

Part 3  |  FIELD Quality Assurance Criteria

A. Inspection

  1. Any light passing the frame perimeter shall be cause for rejection.
  2. Door shall close from 70 degrees and latch freely without latch or hinge bind.
  3. The closing speed for ADA shall not exceed 3 seconds to within 3 inches of the latch position. Lever torque shall not exceed ADA (taken from NFPA 101 Life Safety) of 15 inch pounds.
  4. Filing of strike plates to relieve lock bind is unacceptable.
  5. The "Industry Standards and Recommended Guidelines For Installation" by DHSI shall govern field inspection.

Link to: dhsi-seal.com/roomsecurity.htm for an informative report on current methods being used by thieves to break into rooms all over the USA.

DHSI Products that complete the Quiet Latch Sealing System:

  1. Patented Frame Seals: "Cush 'N' Seal"
  2. Patented Door Bottoms: mortised, security and surface: "AMU" Option: DHSI door bottoms can utilize a patented "Allowance and Means for Undercut" feature blocking light and sound, and still simulate the 3/8" maximum allowable (NFPA) clearance to the threshold.
  3. Patented "Secur-A-Latch" - Due 2002. See our website for two 15 second animated demonstrations.
    a. Eliminates the "Flip Latch" Privacy Keeper which keeps the door from opening but guests use to "prop" the door open to "go get ice." This allows the door to slam and damages the edge of the door
    b. "Secur-A-Latch" quietly disengages when a guest "props" the door open! No damage or complaints!
  4. Thresholds
    a. Economical.
    b. Available in solid colors. Excellent for color separation.
    c. Made of fire rated material.
    d. Eliminates seams in rugs. Exclusive carpet tuck feature.
    e. Available with an "FA/SB", Frame Alignment / Security Bracket.
  5. Other Products
    a. See our website or call DHSI and ask for Owner/President Robert Rissone


DHSI licenses distributors on a selective basis to distribute its competitively priced products and implement the "Quiet Latch Sealing System". Specifications must reference that the GC call DHSI for pricing and/or a list of Licensed Distributors. All distributors, contractors, architects and owners benefit from the 3 Part "Quiet Latch Sealing System." Visit our website DHSI-Seal.com for further information.

Door and Hardware Systems, Inc.

17 Silver Street
Rochester, NY 14611
Phone: 585.235.8543
Fax: 585.235.0431
Email: Info@DHSI-Seal.com