R7 Assembly Seal

R7 Assembly Seal
An "off-the-shelf" balanced internal seal for fuels, oils, chemicals, water and slurries.

Features and Benefits

  • Balanced - The Exact-A-Gen is internally balanced, requiring no special sleeves or costly machining of shouldered shafts.
  • No Fretting - The Exact-A-Gen seal will not fret sleeves or shafts. The 'O' ring on the shaft is static and should any fretting occur from the dynamic 'O' ring, it will be to the carbon holder, the least expensive part of the seal.
  • Easy Installation - One installation dimension is common to all Exact-A-Gen seals, regardless of shaft size.
  • No Exchange - We supply an 'infield' repair kit for a fraction of the original cost. You don't have to send back seals for repair or exchange - this way it costs you less.
  • Fits All AVS/ANSI Pumps - Replaces most seals or packing without pump or gland modification.
  • Isolated Springs - Springs are out of the fluid being pumped, isolated from clogging particles suspended in the product.
  • Non-Clog - Exact-A-Gen has eliminated unnecessary tight clearances leaving the seal open to continual washing by the product up to the 'O' ring.
  • Drive Collar - Exact-A-Gen seal has a large cross section drive collar to eliminate distortion and static 'O' ring leakage.

Technical Data and Dimensions

All standard dimensions will be customized to fit your application.


Shaft Size


seal outboard distance

Stuffing Box ø
C – Min.

1 1.875 1.813
1 1/8 2.00 1.813
1 1/4 2.125 1.813
1 3/8 2.250 1.813
1 1/2 2.375 1.813
1 5/8 2.500 1.813
1 3/4 2.625 1.813
1 7/8 2.750 1.813
2 2.875 1.813
2 /18 3.000 1.813
2 1/4 3.125 1.813
2 3/8 3.250 1.813
2 1/2 3.375 1.813
2 5/8 3.500 1.813
2 3/4 3.625 2.188
2 7/8 3.750 2.188
3 3.875 2.188
3 1/8 4.000 2.188
3 1/4 4.125 2.188
3 3/8 4.250 2.188
3 1/2 4.375 2.188
3 5/8 4.500 2.188
3 3/4 4.625 2.188
3 7/8 4.750 2.188
4 4.875 2.188

SIZES: Metric and sixteenth seals available against specific orders. Larger shaft diameters available against speficic orders.

Material specifications
NO. standard special
1 Chemical Grade Carbon Ceramic
2 316SS
3 Viton Installed
EPR optional
4 Hastelloy C
5 316SS
6 316SS
7 316 SS

Recommended Seal Environmental Controls


Total Warranty

All Robco seals are manufactured to exact standards, and are guaranteed free of defects in materials and workmanship. All seals are guaranteed for 90 days from delivery, excepting negligence, misuse and abuse, and will deliver at our expense a new seal to replace any seal found to be defective within said period. No registration card is required.

The warranty is expressly in lieu al all warranties, expressed or implied, and of all obligation or liabilities on our part, including any liability for incidental or consequential damages.


The temperature limits, pH ranges, pressure ratings, feet per box and shaft speeds shown throughout this pamphlet are representative; the service life and performance of these products can be affected by elevated temperatures and other operating conditions such as chemical resistance, shaft speeds, pressure and equipment in which that the product is being installed. The ratings supplied are suggested as a guideline and should only be used for evaluating your specific application. When in doubt, contact Robco or your ENVIROPAK distributor. The information contained in the pamphlet should not be considered to be a warranty, expressed or implied, including, but not limited to, a warranty of merchantability or fitness for a particular purpose. In no event shall Robco be liable for any incidental or consequential damages resulting from the use, misuse or inability to use the products. This exclusion applies regardless of whether such damages are sought based on breach of warranty, breach of contract, negligence, strict liability in tort, or any other legal theory.

All Robco mechanical seals are manufactured, assembled and tested in America.