Thief Hatch

Thief Hatch

Model L12-TH

Thief Hatch

The Model L12-TH Thief Hatch was designed to out perform the competition, with industry leading high flow rates and precision tolerances to provide a superior sealing performance. The leakage is less than 1 SCFH of air @ 90% of the set pressure, keeping your tanks in compliance with industry standards.

The Model L12-TH Thief Hatch incorporates a spring loaded pressure/vacuum relief valve within the device. Thief Hatches are used on steel or fiberglass (FRP) low pressure oil tanks. Providing access for level gauging, sampling, and overpressure/vacuum protection for the tanks, all in one compact design.


Size: 8" (200 mm)
Bolting: API 12
Available pressure settings: 4, 6, 8, 10, 12, 16, 24 & 32 osig*
Available vacuum settings: 0.4, 0.9 & 3.5 osig

Casting: Aluminum (Non-Sparking)
Envelope Gasket: HNBR, FKM, or Fluorosilicone
Vacuum Diaphragm: HNBR, FKM, Fluorosilicone, or Fluoropolymer

Leak Rate: 1 SCFH air @ 90% of set pressure


*Additional pressure settings available




•   Ultra-tight sealing reduces product leakage and fugitive emissions
•   Higher flow capacity to protect from excessive pressure build up
•   Designed for easy maintenance, thus reducing downtime and lower operational cost
•   Corrosion resistance can be enhanced with FKM soft goods and coating
•   Direct replacement for any standard round API 12 thief hatch (adapters for others  - see options for details)
•   Incorporates a mechanical lock system to be used with a pad lock or lock out bar
•   Bonding strap is standard


Base Gasket:
 GKT12TH08K302       =    Non-Asbestos
 GKT12TH087602       =    FKM
 GKT12TH087102       =    PTFE
 GKT12TH084402       =    Black Neoprene
 GKT12TH083502       =    Buna-N
 GKT12TH08CJ02       =    FKM (Blue)
 GKT12TH08BO02      =    Fluorosilicone

Mounting Kit:
 KS12THBS08P01       =    Hex Nut and Bolt Set - Zinc Plated Steel
 KS12THBS08P02       =    Hex Nut and Bolt Set - 18-8 Stainless Steel

Flange Adapter:
 ADP12TH080101       =    Flange Adapter - 8” 150# ASME to 8” API 12 - Aluminum
 ADP12TH082001       =    Flange Adapter - 8” 150# ASME to 8” API 12 - Carbon Steel
 ADP12TH082002       =    Flange Adapter - 8” x 18” Oblong to 8” API 12 - Carbon Steel
 ADP12TH082003       =    Flange Adapter - 8” x 22” Oblong to 8” API 12 - Carbon Steel

Y Adapter:
 ADP12TH080104       =    Y Adapter - 8" API 12 - Aluminum


Thief Hatch

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Thief Hatch

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