View Ports / Peep Doors / Sight Ports

Need Peep Doors or Sight Ports? Contact FIS for Specs, Lead Times, and Quotes.

Request More Information
Request More Information
View Other Spare Parts
View Other Spare Parts
Exploded view of a high-voltage electrical switch with internal components and wiring, mounted on a green panel.

Learn More About Furnace Improvements Services (FIS)

Patented technology • Measurable ROI • Trusted by top refineries

Our Services

  • Fired Heater Revamp

  • Boiler Revamp

  • New Heater and Boiler Design

  • In-person and Virtual Training

  • Decarbonization Solutions

  • Engineering Studies

  • Trouble Shooting

Our Scope

  • Process Engineering

  • Mechanical Engineering

  • Structural Engineering

  • 3D Modeling

  • CFD Modeling

  • Project Management


500+

Heater Studies completed

29

Years in Business

15

Countries Served

4

Patented Technologies

2

Global Offices

By The Numbers:

Overview

  1. Peep doors (also called view ports, sight ports, or observation ports) are provided in the radiant section of the heater to allow viewing of burner flames, tubes, tube supports, and refractory.

  2. Critical areas of observation include burner flames and pilots, the hottest portion of tubes.

  3. Peep doors should be accessible either from the Grade or from platforms.

  4. We have an extensive list of references for our Peep Doors — a selection is publicly available here

    Download our brochure

Glass Peep Door

  • Consists of a front high-temperature glass pane, a handle and a flap.

  • Pull down the handle to lift the flap behind the glass pane.

  • The operator can look into the firebox through the glass pane.

  • The glass pane is heat and breakage-resistant.

Side-Hinged Peep Door

  • Consists of a spring handle, side-hinged door, and locking lever.

  • The door contains ceramic fiber packing with a SS Liner.

  • The locking lever ensures tight closing of the door.

  • The operator has to unhook the locking lever and open the door

Top-Hinged Peep Door

  • Consists of a spring handle and a top-hinged door.

  • The hinged door contains ceramic fiber packing with a SS liner.

  • Lift the spring handle upwards to open the door.

Peep Door Blocks

  • Peep door blocks are made from a special vacuum manufacturing process. These offer the best strength and rigidity.

  • Peep door blocks are mainly made from Folded blanket module.

FIS offers a wide range of customizable peep door solutions to suit your unique application needs. We work closely with our customers to deliver precision-engineered doors tailored to their exact specifications.

Customizations include:

  • Peep door size and arrangement

  • Material of construction

  • Accessories and add-ons

  • Placement and orientation of components

  • Design modifications to existing parts

  • Supply of entirely new peep door designs as per customer specifications

A detailed pump with a yellow base and a red and beige front panel, equipped with multiple bolts, a mesh screen, and a handle.
An electrical fire alarm with a yellow cover, labeled "FIS," mounted on a wall with green protective plates. The alarm features a lock with a key, a cord, and a pin in a safety position.
Fire alarm device installed on a wall with wiring and a manual pull station.
A mechanical fixture with colorful components attached to a large block. The fixture includes a yellow piece with a logo, a blue handle, a spring, and various screws and bolts, suggesting it is part of a machine or machinery setup.
A yellow emergency shut-off switch mounted on a wall panel with a pink safety pin and a coiled safety lanyard hanging below.
Exploded view of a mechanical or electronic device with multiple colorful components, including a yellow frame, gray and blue parts, and black screws.
A safety interlock switch attached to a machine enclosure, with a yellow guard, a tester, and a spring-loaded mechanism, used for machinery safety.
A safety switch or emergency stop button mounted on a green wall, with a bright yellow cover, a pink lever, and a coiled blue cord hanging below.
Close-up of a mechanical or hydraulic component mounted on a pale green wall, with a yellow rectangular mounting plate, a green circular part with a hollow center, a coiled blue wire, and various bolts and connectors.
Exploded view of a mechanical or electronic device with various parts including a yellow frame, black panel, mesh screens, screws, and other small components.
Exploded view of a mechanical device with multiple colored parts, screws, and a rectangular frame, showing internal components and assembly layers.
Exploded view of a complex electronic device with multiple components, including screws, circuit boards, and various colored panels.
Exploded view of mechanical assembly with various colored parts and fasteners.
Exploded view of a mechanical or electronic device assembly with various parts, including a yellow bracket, a grid-like metal piece, a large light grey panel, smaller screws, washers, and other components.
Exploded view of mechanical or electronic device showing various colorful components, screws, and a spring.
A detailed exploded view of a mechanical assembly with various colored parts, including yellow, red, blue, green, and gray components, bolts, washers, and a spring, illustrating the assembly process.

Other Peep Door Configurations

Wire Mesh Glass Peep Door (17 1/2” X 6 1/2”)

Single Hinged Glass Peep Door (7” X 11”)

Double Hinged Glass Peep Door (7” X 11”)

Top Hinged Peep Door (5” X 9”)

Circular Glass Peep Door (2'' Φ )

Side Hinged Peep Door (11 5/8” X 15 9/16”)

Side Hinged Peep Door (9” X 24”)

Side Hinged Peep Door (3 13/16'' x 5'')

Need Peep Doors or Sight Ports? Contact FIS for Specs, Lead Times, and Quotes.

Request More Information
Request More Information