special bolts and gasket materials     •     axnp field assembly procedure

Erection of an installation of AX Sections is very easily accomplished. No special tools or elaborate rigging are required to set them in place.

For a sprayed system, a minimum of two feet clear all around and four feet between rows of stacks (not between adjacent stacks in a row) generally should be provided in designing the catch basin. An equal amount of free access space should be provided in designing a box for submerged operation. For an evaporative system four feet or more outside clearance is generally allowed, with six feet clearance between rows of stacks.

Simple supporting members, usually concrete piers integral with the pit, but also I-beams, rails or timbers, two per row of stacks, are all that is required for the foundation.

In erecting, it will be noted that the mating gasket surfaces of Sections are ground at a slight angle to the lateral center line. This provides slope for drainage of the contained fluid. Simple metal shims 1/2" thick under each Section at the supporting members will level the flanges, and will automatically insure plumb connections and proper drainage. By careful setting of the bottom Section, correct alignment of the entire stack is assured.

Care should be taken that the adjacent process piping does not put the stacks of Sections or their manifolds in shear. Good piping practice to eliminate thermal stresses will accomplish this end.

In making up joints between sections with gaskets, the inside bolt should be tightened first. Approximately eighty foot pounds of torque are required on each bolt for adequate gasket compression.


See the following paragraphs for push nipple assembly.


A variety of bolting and gasket materials are available for different types of corrosive service. Steel bolts and composition asbestos gaskets are furnished as standard. Bolts can be coated for service with sea or harbor water. More costly non-ferrous alloys or stainless steel bolting is also available on special order. For high temperature corrosive service, solid or envelope-type Teflon® gaskets are normally used, and other types of material are available on special order. Where push nipple joints are used on Sections, the special gaskets would be applicable only to the joints on the manifolds. A gasketless joint, using cast iron push nipples between Sections, is furnished as a special item. Sections and fittings machined for this arrangement are designated by the suffix NP after the part number.


For best results, the following procedure should be followed in field assembly of AXNP AX acid cooler sections:

  1. Place the first section on a flat surface and remove the protective tape from the face of the nipple port.

  2. Check carefully for any possible burrs on the nipple ports and file same with a fine file to insure a perfectly smooth surface.

  3. Clean nipple ports of all dirt or other foreign matter that may have accumulated in transit or at job site storage.

  4. Apply a coating of SAE 10 or pressing oil on the cast iron nipple and nipple ports. Thubin oil is recommended and used on all factory assembled jobs.

  5. Place the oiled nipples in the nipple ports, fitting them in place carefully to prevent cocking. Using a rawhide hammer, tap the nipples in place until properly seated.

  6. Clear burrs and clean nipple ports on the second section and place on top of the first section, fitting the grooved lug into the first section and nipple port directly over the protruding nipple from the first section.

  7. Insert the bolts in the three bolt openings and attach nuts thereto, carefully tightening the nuts in an even cycle so as to prevent nipple from being cocked. Inside bolt should be tightened first, then rotate to outside bolts and continue cycle until all bolts are completely secured. A cocked nipple will cause section to leak.

  8. Repeat this procedure with each section added to the stack until the desired number of sections is attained.

Installing SEMI-STACKS of partially factory assembled sections:

Clear burrs and clean out cast iron nipple ports of the top casting same as described for single section above.

Apply light machine oil same as item #4 above.

When lifting a battery of sections, whether a hi-lift, cherry picker, or any other means, always grip the bottom or as near to the bottom section as possible. By inserting the forks of a hi-lift or applying slings from a cherry picker midway or higher in the assembled stack can sometimes jolt the lower sections and cause them to work loose and eventually leak.

Attach the two stacks together as described in item #7 above.

All nuts should be checked on semi-stacks at time of installation to be certain that none were loosened in transit or during installation.