A Leader in Radiation Shielding Materials


Continuous Hinges

A geared continuous hinge is the hardware of choice for lead lined doors. Pitts Little proudly stocks high quality Roton® Continuous Hinges produced by Hager. All hinges are fire rated and include the manufacturer’s lifetime warranty. These hinges work perfectly in combination with Pitts Little Lead Lined Doors and Pitts Little Lead Lined Door Frames and are also available for individual purchase.

We typically carry a large inventory of Roton® 780-224 LL concealed leaf continuous hinges for lead lined doors with a clear satin anodized finish in the following sizes:

  • 79″ (for 6’8″ doors)
  • 83″ (for 7’0″ doors)
  • 95″ (for 8’0″ doors)


Roton 780-224 LL Datasheet

Pitts Little Corporation provides custom fabrication for the following products. Please click on an item below to learn more.

These images represent Duct Shielding in a high energy vault. This type of shield is employed to attenuate neutrons when air ducts penetrate the vault wall.

Our Direct Shield 6 MV Door allows the clinic to maximize space and avoid the need for an elaborate concrete maze. The Pitts Little Sliding Door incorporates the latest mechanical and technological improvements available. These doors are typically used for Cyber Knife, High-Dose-Rate (HDR) Brachytherapy, Gamma Knife, TomoTherapy Image-Guided Radiation Therapy (IGRT), Intensity-Modulated Radiation Therapy (IMRT), Stereotactic Radiosurgery (SRS) for Spine and Lung and External Beam Radiation Therapy applications.

Custom Steel Construction

A-36 material, heavy duty frames and ¼” and 3/8″ cover plates.

Door Contents

ASTM B29 LEAD with removable back panel for shielding design changes.

Door Operator (Operating System)

Uses an electric motor with batter back-up for uninterrupted service. Battery power will allow door to open only.

Standard Safety Features

  • Safety bumper with a minimum 2″ crush zone
  • Battery backup
  • Interlock Switches
  • Other options available upon request.

All components for the door fabrication and installation are manufactured and installed by Pitts Little’s skilled craftsmen, who will install all mechanical and technical components. All wire and conduit will be furnished by the electrical contractor.

All doors are warranted against defect for at least one year.

Custom designs available upon request. Contact us to learn more.

More Information

Cyclotrons are particle accelerators used to produce radioactive isotopes. Cyclotrons typically produce a high neutron population and gamma rays. Two major fields that Pitts Little works with cyclotron owners are: for research institutions and for the radiopharmaceutical industry. Pitts Little Corporation is frequently employed to help solve complex shielding issues surrounding cyclotrons. Not only does Pitts Little shield the cyclotron chamber, we also shield the beam line, target rooms and delivery lines. Pitts Little has also been called on to mitigate shielding issues discovered on cyclotron startup.

The electron beam door pictured weighs approximately 250,000 lbs. and is basically a moving linear accelerator vault wall. Pitts Little Corporation collaborated with the owner’s design team to design, construct and install this door and the automatic drive system. We have seen an increase in electron beams being considered for manufacturing. The specialized applications of industrial electron beam accelerators require each installation to be unique. Pitts Little Corporation will be happy to discuss your electron beam project.

The physicist of record must determine all shielding for the vault. A typical cyclotron vault plug door is approximately 5′ wide by 8′ high and 5′ thick.

Main Components

Steel Door Case welded ½” HRP with internal bracing.
Flanged 5”Dia. Steel Wheels w/Tapered Double Roller Bearings.
Door Frame – ½” HRP welded w/integral steel studs for welding to rebar.
Drive System – Gearmotor AC inverter drive.

  1. Load bearing rails to be permanently mounted in the floor.
  2. Control System –
    1. Inverter Drive w/ acceleration &deceleration Ramps.
    2. PLC Control – programmed for proper Operation and integrated w/ Safety System
    3. Push Button Controls outside Vault with following Functions.
      1. Open.
      2. Stop.
      3. Close.
    4. Push button controls inside will have the following functions
      1. Open.
      2. Stop.
  3. Manual Emergency opening device.
  4. UPS for Power out Operation of Door.
  5. Safety System to include –
    1. Light Curtain at Opening.
    2. Pressure Sensor at each of 4 Corners of the Door.
    3. Presence Sensor above Door Opening.
    4. Visual and Audio Tower for door movement.
  6. Power Control Panel
    1. Remote Control Switch.
    2. Overload cut-out.
    3. Fused magnetic Circuit breaker.
  7. Operating Parameters
    1. Operating Time 45 seconds to Full Open.

Pitts Little Corporation will provide the Door Frame, Door Case, Door Drive System, Control System, Push Buttons, Light Curtain, Presence Sensor, Flanged Rollers, Rail system and other items to make a Complete System.

Installation by the Contractor

The contractor will be responsible for installing the frame that we supply.
All concrete and grout is by others.
The plug door is to be concrete filled by others.

The following cyclotron Interlocks are by others:

  1. Signal to Prevent Beam Activation if Door is Open
  2. Signal to Prevent Beam Activation if Operators have not Exited the Bunker
  3. Prevent Door Operation if Beam is On
  4. Disable Cyclotron Operation

Submittal drawings will be provided after an order is accepted. The owner is to evaluate the door construction tolerances and drive functions prior to fabrication.

Specifically Excluded:
Demolition, Utility relocation, All Concrete work, Setting the frame, Physics, All conduit and wiring, Duties, Tariffs and Taxes.

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