Technical Info :: Handling and Installation

(361) 572-4040


Handling and Installation Recommendations

The following Diamond Fiberglass handling and installation instructions are designed to help customers install fiberglass chemical storage tanks properly and in a minimum of time. Proper handling and installation are extremely important for long corrosion resistance and low maintenance over the tank life. Handling and installation instructions outlined in this bulletin are only recommendations and do not relieve the Purchaser from full responsibility for the proper inspection, handling and installation of the tank. Unknown situations and conditions not covered in this bulletin are also the responsibility of the Purchaser. Failure by the Purchaser to take the precautions outlined in these instructions will invalidate the tank warranty.

Shipment via Diamond Fiberglass truck will be considered complete when the truck arrives at the jobsite and prior to removal of the tanks by the Purchaser. Diamond Fiberglass employees or representatives will not direct nor be responsible for the removal of tanks from commercial or Diamond Fiberglass' own trucks. The presence of a Diamond Fiberglass employee or representative at the delivery or installation site does not relieve the Purchaser of any of his responsibility for the proper handling and installation.


Diamond Fiberglass will take every precaution possible when preparing a tank for shipment. Normally, our tanks are shipped on our own trucks. Small, open top, vertical vessels will not be covered for shipment unless so specified by the customer. Movement will be by lifting lugs, if specified, in the case of closed top tanks, eye bolts in the case of open top tanks, or the tanks may be installed on a pallet. If the tanks are installed on a pallet, they will be bolted or strapped to prevent movement. Large vertical and horizontal tanks are shipped in a horizontal position.


The customer should arrange for an inspector or a responsible person at the jobsite to inspect and also supervise the offloading of the tank. If damage has occurred during transit, it should be noted on the bill of lading prior to signing acceptance. If damage has occurred, a claim should be filed promptly with the delivery carrier by the Purchaser. If no claim is filed, the customer accepts all future responsibility for a damaged tank. If damage has occurred and is not first repaired by Diamond Fiberglass prior to the tank being put into service, the Purchaser accepts all future responsibility for the effects of tank failure resulting from such damage.


The following should be used as a guideline in making an inspection of the tanks prior of offloading. Inspection should be made both inside and out.

  • a. Check the load for any signs of breakage, abrasion, shifting or rotation that may have resulted in damage to the tank
  • b. If shipping cradles are used, check for any signs that they may have moved, shifted or rotated resulting in cracks or crazes at point of contact.


Diamond Fiberglass tanks are designed to withstand normal handling procedures. Here are some normal precautions to follow to prevent damage to the tank.

  • a. Operators of hoist equipment should follow proper rigging procedures at all times. Care should be taken to prevent the tank from swinging out of control.
  • b. Always lift- never roll or slide a tank.
  • c. When moving a tank, do not drop or allow hard impact.
  • d. Never let tools strike or drop on either the inside or the outside of the tank.
  • e. Ladders used inside the tank should be wood or have rubber protectors.
  • f. Workmen entering a tank should wear soft-soled shoes.
  • g. Never use cables or chains around the tank.
  • h. Never lift a tank by using any fittings or appurtenance other than the lifting lugs. When lift lugs are not provided as part of the equipment, woven fabric rigging slings of 3-inch minimum are recommended.
  • i. In storing tanks prior to installation, tiedown securely. Tank should be placed only on firm level surfaces which are free of stones, tools and other small hard objects, because these cause high stress points. When stored outdoors, tanks should be adequately secured to prevent movement due to wind or water flotation.
  • j. Do not allow cables, hooks or spreader bar to swing against the tank.


A spreader bar and lines to appropriate lifting lugs, or a clevis and lines to lifting lugs shall be used to unload tanks shipped on a flat bed trailer or one of our specially designed padded saddle trailers. The angle between the lifting lines and top of tank must always be 60o or greater. When lifting lugs are not provided, tanks should be lifted off using two canvas or nylon slings or straps and a spreader bar, which is attached to the hoist cable.

Large tanks should be righted by hoisting with a spreader bar and lines to the lifting or clevis and lines to lifting lugs. Adequate padding is necessary to protect the pivot point. Workmen should keep control over the tank with guidelines to insure the tank is gently brought to rest upon its base. Use a spreader bar and lines or clevis lines to appropriate lifting lugs to move tank when in an upright positing. Insure size of lifting equipment, lines, clevis' are capable of handling the weight of the tank. Insure size of lifting equipment, lines, clevises, are capable of handling the weight of the tank.

ON-SITE STORAGE (Before Installation)

  • a. Vessel can be stored in either the vertical or horizontal position, whichever site conditions allow.
  • b. Should the vessel be stored in the vertical position, it must be anchored or tied-off to prevent it from overturning. The vessel's lower flanges can be blinded and the vessel filled with 1 to 2 feet of water to weigh it down. If preferred, the vessel lifting lugs can be used as 'guy' points to tie the tank off to anchor points.
  • c. Should the vessel be stored in the horizontal position, it should be tied-off or strapped to prevent rolling due to wind. Standard flat bottom, dome or flat top tanks can be set directly on the ground, provided fittings and accessories do not interfere. Chock the vessel with wood blocks, tires, etc. at the top and bottom knuckles. Do not set the vessel on blocks or timbers, especially if they are away from the top and bottom knuckles. Use ropes or nylon straps to tie-off the vessel. Do not use cable or chains.
  • d. Leg supported cone or dish bottom vessels can be stored either vertically or horizontally. Should they be stored either vertically or horizontally, the same procedure above can be used. Once the vessel is set, the support legs can be blocked, chocked, or tied-off to prevent roll-over.
  • e. Skirt supported or open top tanks with stiffening 'leg-out' flange(s) stored in the horizontal position must have the ground 'trenched out' to allow for the flange, to prevent the load of the vessel being carried by the flange. If this is not possible, the vessel may be set on soft blocks (tires, foam board, etc) provided the blocks are set adjacent to the stiffening flange(s). If this is not possible, the vessel must be stored vertically, and tied-off as previously noted to prevent overturning.


  • a. The support base for flat-bottomed vertical vessels should provide full and uniform support over the entire bottom area. The support base should be properly designed to prevent settling or deflection under maximum design loads.
  • b. The support base surface should be nonporous and free of cracks, depressions and vertical projections. Reinforced concrete, trowel finished to American Concrete Institute Specifications (ACI- 301-72, Section 11.7.3, "Trowel Finish") is often used as a support base.
  • c. Vertical equipment having a cone or dished bottom will have an alternate type of mounting arrangement such as a FRP or steel skirt, or legs. These must be considered as special cases, for each unit will have its own condition of load concentration. Special support design is therefore required for each individual installation.
  • d. Each flat bottom unit should be set on a cushioning pad to minimize stresses caused by seams, shrinkage distortion, and/or support base irregularities. Where irregularities are less than 1/2 inch (12.7 mm) in depth; several layers of 30 lb. roofing felt equal in diameter to the outside diameter of the equipment plus 2 inches (0.0. + 2 in.), should be laid directly on the surface of the support base. The center of the pad should be built- up by the addition of two layers of the same material, one equal in diameter to 1/2 and the other, 1/4 the diameter of the equipment, Figure 3.
  • e. A suitable elastrometric sheet material of proper environmental resistance may be substituted for the roofing felt.
  • f. Where irregularities in the surface of the support base are greater than 1/2 inch (12.7 mm) in depth, an asphalt type of paving mastic can be troweled into these areas and pressed or tamped to provide a reasonably hard, flat and level surface. Time should be allowed for the mastic to harden (4 hrs. minimum) before the first layer of roofing felt is applied.
  • g. Where a vessel has a bottom drain, provisions should be made in the base pad with clearance so that contact will not occur between the pad, the nozzles or nozzle flange.
  • h. Where a trench in a base pad is required to accommodate bottom discharge piping, a structural trench cover should be installed flush with the top of the base pad to minimize the unsupported area of the tank.
  • i. All flat bottom equipment should be secured in place by bolting to the base pad through hold down lugs. This precaution will minimize the chance of equipment damage at nozzle locations and areas of other attachments due to movement of the unit. Hand tighten bolting, fill tanks with water, then torque to 25 ft-lbs. DO NOT tighten down hold down lugs until tank is filled.
  • j. All vessel nozzles below the liquid level should be joined to piping through a flexible connection. A shutoff valve should be connected directly to the nozzle with a flexible bellows or hose joining the valve to the piping.
  • k. Valves, which are attached to tank nozzles, should be independently supported so that closing and opening of a valve does not transmit the total torque load directly to the nozzle.
  • l. Flanged nozzles have standard ANSI 150 Lbs. flange bolthole arrangement. Full-face gaskets are to be used. Gasket material exceeding 70 durometer (and less than 1/8") should not be used.
  • m. Metal washers should be used under all bolt heads and nuts, which would otherwise be in contact with the FRP flanges.
  • n. Nut and bolt threads should be lubricated before tightening.
  • o. Bolting take-up torque should be applied uniformly, alternating 180 degrees and rotating as near 90 degrees as possible. A bolt torque pressure of 30 ft. Lbs. will normally be sufficient to affect a seal.
  • p. Precautions must be taken by the customer to insure the supplied vent is not restricted in any way during the service life of the vessel. The customer is solely responsible for insuring adequate venting is achieved. Modifications to the originally supplied vent must not be made without consulting Diamond Fiberglass Fabricators.


  • a. Agitators, mixers, coils, etc. must be adequately supported as approved by Diamond Fiberglass Fabricators.
  • b. External piping to the vessel must be adequately supported to insure that stresses are not imposed on vessel nozzles.


  • a. Before allowing personnel to enter vessel, be certain that all applicable confined space entry procedures are being complied with.
  • b. Insure that all valving and plumbing is either disconnected or 'locked out' before allowing vessel entrance.
  • c. Insure that vessel is adequately vented.
  • d. Be sure any foreign objects, dirt, pebbles, etc., are removed from the vessel so they will not mar the interior surface.
  • e. Personnel entering the vessel should wear soft soled shoes, free from any debris that could injure the interior surface (pebbles, nails, etc.).
  • f. If a ladder is used for entrance, it should have padded feet. Do not rest the ladder on the internal components or point load its base surface.
  • g. Care must be taken not to drop or bang objects against the vessel.
  • h. When walking in the vessel, make sure any areas which flex do not rest against sharp objects. Use padding where necessary.
  • i. Never use any component, internal or external, for climbing or standing unless it is specifically designed for this purpose.