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Tank hatches



Tank hatches and cleanout holes are operating equipment and are necessary for operation and maintenance of vertical or horizontal tanks and vessels.

The Saratov Reservoir Plant supplies equipment of its own production:

  • gauging hatches LZ
  • light hatches LS
  • manhole hatches LL
  • bottom cleanout boxes
  • cleanout holes

The application and design of tank hatches

Their main function is to provide access to the tank or vessel for maintenance and repair. In terms of design, they have a round or oval shape. The inner edge should have a coating that does not form sparks of friction resulting from Sampling equipment and measuring devices moving.

Gauging hatches LZ are designed for mounting of equipment to determine the oil level or sampling. Hatches LZ are installed on the mount nozzle or the neck. To prevent unauthorized access, tamper-evident sealing may be performed. The Plant supplies two sizes of LZ hatches: LZ-80, LZ-150.

Gauging hatch LZ Criteria LZ–80 LZ–150
Gauging hatch LZ drawing Nominal diameter (neck diameter), mm 80 150
Overall dimensions, mm:
diameter, D 185 260
width, L 226 285
height, Н 185 240
Connection size, mm:
D1 150 225
d 18 18
n 4 8
Weight, kg, max 2,3 5

Light hatches LS are installed on the inlet - distribution nozzle for the light access inside, ventilation during defects examination or cleanout, maintenance control or repair. The sealing of the tank hood is guaranteed by the tightening.

Light hatch LS Criteria LS-200 LS-300 LS-400 LS-500 LS-500П LS-600 LSC-1000
Light hatch LS drawing Nominal diameter DN, mm 200 300 400 500 500 600 1000
Overall dimensions, mm, max diameter D 350 455 535 640 640 760 1175
height H 362 500 4462 562 600 562 603
Reinforcing plate diameter, mm, max 440 650 860 1100 1100 1160 1500
Weight, kg, max 32 55 69 104 110 140 200

Manhole hatches LL are mounted in the first ring of the vertical tank to provide maintenance control or repair. Installation of LL hatches on tanks with a pontoon or floating roof is carried out to provide access to the roof. The hatches are equipped with davit arms and have a tightening to seal the hood. Plant SARRZ supplies manholes LL in the following sizes depending on the tank capacity: LL-500, LL-600, LL-800, oval manhole LL 600x900.

Round manhole hatch LL Oval manhole hatch LL
Round manhole hatch LL drawing Oval manhole hatch LL drawing

Bottom cleanout boxes are installed in the lower ring of vertical tanks and are used for bottom sediments removal. The cleanout boxes provide access to perating personnel to the inside to carry out maintenance and repair. Especially this type of hatches is essential for normal operation of vertical tanks for viscous oil storage. The Plant SARRZ supplies bottom cleanout boxes in three sizes: 600x600, 600х900, 900х1200. (full details you may find here)

Drawing of bottom cleanout box 600x900

Cleanout holes are used for bottom sludge removing of vertical tanks or sludge generated in the interstitial space of the tanks with a protective wall ("a glass in a glass"). These holes are mounted under the bottom or the shell of the tank. The exact layout depends on the type of bottom: in tanks with a bottom pitch from the central point the cleanout hole is installed next to the shell within 500 mm; in tanks with a bottom pitch to the central point it is mounted under the bottom in the center; in tanks with flat bottom it is buried in the catch pit under the shell. Depending on the operating conditions, we complete the tanks with a trough or round cleanout holes.

Criteria D50 D80 D100 D150
Pipe diameter 57 89 108 159
Pipe wall thickness 5 5 5 6
Diameter 600 900 1200 1500
Depth 300 450 600 900
Plates thickness 8 10 10 12
Round cleanout hole Trough cleanout hole
Round cleanout hole drawing Trough cleanout hole drawing

Hatches and cleanout holes supplied by the Saratov Reservoir Plant provide:

  • large amount of open/close operation cycles (time to failure)
  • interface integrity and joint tightness
  • high corrosion resistance of steel grades used
  • trouble-free performance throughout service life of the equipment

The hatches and the holes are supplied optionally together with a vertical tank at the Customer's request. It is possible to order manufacture of manholes and hatches separately.

How to purchase hatches for a vertical tank of any design?

In order to calculate the cost of gauging hatches LZ, light hatches LS, manhole hatches LL, bottom cleanout boxes, cleanout holes, You can:

  • call at +7(8452)250-288
  • e-mail at  with equipment request
  • use the form "Request for quotation"


See also:

Breather valvesSamplersTank hatches
Bottom cleanout boxesNozzles, nipples, connecting pipes, fittingsFlame arresters
Tank clap valves