In the daily work of water and sewer operators, the need arises to block certain pipeline sections in order to carry out repairs, connections, new nodes or pressure tests.
What devices are used in such cases?
The most common devices are pneumatic pipe stoppers of various types.
We have even encountered pilates balls used as stoppers… for those who go to the gym more often…
Ing. Viktor Szokoly
General Manager Proex Top SRL
Regarding the pneumatic stoppers, the most widespread are cylindrical models which, when inflated with compressed air, increase their diameter and thus seal the end of the pipe.
Cylindrical stoppers
Cylindrical stoppers - technical sketch
Since cylindrical variants are widely known and previously presented, we propose focusing on volumetric pneumatic stoppers.
Volumetric Pneumatic Pipe Stoppers
Volumetric pneumatic stoppers
What are user expectations for such devices? Here are a few:
- To be universal, one stopper covering all relevant pipe diameters;
- To be lightweight and easy to install;
- To require no additional devices;
- To be usable for any pipe or channel geometry;
- To be usable indefinitely.
Volumetric pneumatic stoppers, compared to cylindrical ones, are constructed for the maximum diameter, and by folding them, they can also cover smaller diameters.
Based on this principle, volumetric pneumatic stoppers offer a substantial number of advantages compared to cylindrical models.
1. First requirement – universality:
For example, the Type 1-1500 stopper, covering diameters from DN 500 to DN 1500, weighs only 28.2 kg. It is not a universal solution, but compared to the cylindrical variant, it allows the same device to be used for 2–3 additional diameters. To cover a range from 500 mm to 1500 mm with the cylindrical version, two different devices would be required.
Furthermore, if we consider, for example, the range from 400 mm to 1000 mm, the situation is the same: two cylindrical stoppers would be required to cover the same diameter range.
| Model | DN | DN | v1 | v2 | v3 | v4 |
|---|---|---|---|---|---|---|
| 1-150 | 80 mm (3 in) | 150 mm (6 in) | 76311 (0.9 kg) | 76312 (1 kg) | 76313 (2.3 kg) | 76314 (2.4 kg) |
| 1-400 | 100 mm (4 in) | 400 mm (15 in) | 76326 (1.9 kg) | 76327 (1.93 kg) | 76328 (3.55 kg) | 76329 (3.6 kg) |
| 1-600 | 200 mm (8 in) | 600 mm (23 in) | 76336 (3.9 kg) | 76337 (4.1 kg) | 76338 (11.8 kg) | 76339 (12 kg) |
| 1-800 | 300 mm (12 in) | 800 mm (31 in) | 76341 (7.2 kg) | 76342 (7.6 kg) | 76343 (17.4 kg) | 76344 (17.8 kg) |
| 1-1000 | 400 mm (15 in) | 1000 mm (40 in) | 76346 (11.8 kg) | 76347 (12.4 kg) | 76348 (23.7 kg) | 76349 (24.3 kg) |
| 1-1200 | 500 mm (20 in) | 1200 mm (47 in) | 76351 (14.5 kg) | 76352 (15 kg) | 76353 (28.5 kg) | 76354 (29.2 kg) |
| 1-1400 | 500 mm (20 in) | 1400 mm (55 in) | 76356 (25.2 kg) | 76357 (27.9 kg) | 76358 (41.5 kg) | 76359 (44.2 kg) |
| 1-1500 | 500 mm (20 in) | 1500 mm (59 in) | 76365 (28.8 kg) | 76366 (29.8 kg) | 76367 (45.1 kg) | 76368 (47.8 kg) |
| 1-1600 | 600 mm (23 in) | 1600 mm (63 in) | 76361 (38.5 kg) | 76362 (41.8 kg) | 76363 (56.7 kg) | 76364 (58.5 kg) |
| 1-2200 | 1000 mm (40 in) | 2200 mm (87 in) | 76376 (86 kg) | 76377 (90.4 kg) | 76378 (105 kg) | 76379 (109.4 kg) |
| 1-2800 | 1500 mm (59 in) | 2800 mm (110 in) | 76391 (132 kg) | 76392 (138 kg) | 76393 (152 kg) | 76394 (158 kg) |
| 1-3200 | 1800 mm (71 in) | 3200 mm (126 in) | 76396 (179 kg) | 76397 (186 kg) | 76398 (200 kg) | 76399 (207 kg) |
| 1-3600 | 2200 mm (86 in) | 3600 mm (141 in) | 76381 (216 kg) | 76382 (224 kg) | 76383 (245 kg) | 76384 (253 kg) |
2. Easy to install:
As seen in the table, volumetric pneumatic stoppers have an extremely low weight compared to cylindrical ones for the same maximum diameter.
Another benefit is the way they are packaged and delivered.
Folded volumetric pneumatic stopper
Volumetric pneumatic stoppers - installation
In the image above, a stopper for a maximum diameter of 2200 mm is inserted into a 600 mm manhole. A comparable cylindrical stopper for the 800–1800 mm range has a minimum relaxed diameter of 600 mm and a length of 3.1 m. Just try to imagine how such a device could be inserted through the manhole opening and access shaft!
3. No additional devices or accessories required:
For cylindrical stoppers, you will always see the marking above with the warning: Install support devices!
Without these devices, which usually are not purchased with the stoppers, personnel are exposed to serious work accidents.
Support device for cylindrical stoppers
Volumetric pneumatic stoppers - anti-slip belts
In the case of volumetric stoppers, such devices are not required, as the volumetric version features one or more “belts” made of foamed rubber, which is highly abrasive and prevents slipping, while also ensuring a 100% seal.
4. Usable for any pipe/channel geometry:
Because of their operating principle, volumetric stoppers conform to the shape of the cavity they seal. This would be extremely difficult or impossible with cylindrical stoppers.
5. Long-term usability:
Conventional stoppers are made from synthetic rubber compounds (SBR, NBR, etc.) containing additives and are hot-vulcanised. For this reason, similar to car tyres, the material experiences stress in the form of accelerated ageing. While a patch can sometimes be applied to the inside of a tyre, this is effectively impossible with conventional stoppers.
Cylindrical stoppers, hot vulcanized
Aging phenomenon – hot-vulcanized rubber
Volumetric pneumatic stopper – repair kit
In contrast, volumetric stoppers are manufactured by cold vulcanisation from 100% pure Neoprene (CR). As a result, any puncture can be easily repaired using patches and a repair kit. A stopper of this type can achieve a service life exceeding 35 years.
In conclusion, we believe we have provided sufficient arguments to draw attention to this type of equipment and tools. Should any of you wish to conduct operational tests with these devices, we are ready to demonstrate that the statements above are not mere claims.