Robco Expert

  What is standard API 622? By J.Melançon - Robco Inc. API 622 is a standard developed by the American Petroleum Institute (API) that specifies the requirements for the design, testing, and performance of packing systems used in rising stem valves for fugitive emissions control. Specifically, API 622 provides guidance on the design and testing of valve packing systems to reduce fugitive emissions from valves used in volatile organic compound (VOC) and hazardous air pollutant (HAP) service. The standard specifies the minimum performance requirements for the valve packing, such as maximum allowable leakage rates, as well as the test procedures to be used for evaluating the performance of the packing system. API 622 is intended to provide a consistent and reliable approach for controlling fugitive emissions from valves, which is an important aspect of environmental and safety management in the oil and gas industry. Testing API 622 specifies several test procedures to evaluate ...

  How to Simply Seal the Door of an Industrial Oven with a Tadpole Tape Gasket ? By: Jocelyn Vachon  VP Innovation Group - Robco There are a variety of types of industrial ovens with various door geometries. To seal the heat (radiation, convection, conduction) inside the oven, a flexible gasket is often required. Some ovens incorporate a groove to place an insulating rope. Also, strips or extrusions made of polymers from silicone or fluorocarbon can operate at relatively high temperatures. The most viable option, however, is a tadpole tape gasket. But, what is a tadpole tape gasket? What are the materials used ? A tadpole tape gasket consists of mineral-based textile materials (fiberglass, silica, ceramic) made into a seal starting with a core made of an insulating rope, surrounded by a sown fabric, the ends of which are allowed to extend (see graphic). A wire mesh can be added to the surface, to protect the fabric from excessive wear. Alternatively, a core of knitted metal wi...

As a rule of thumb,70% of shaft wear from braided packing is caused by the first and second rings adjacent to the gland follower. Why? Imagine you had 4 identical full cardboard boxes in a row and pushed on the first one, all 4 boxes would move as one. Packing does not react that way, as compressible braided packing needs to densify sufficiently to push on the next ring and so on. It is the bottom ring in the stuffing box that needs to be compressed in order to produce an efficient seal. But how can you get the load from the gland follower to this ring? The answer is to use die-formed, or pre-compressed packing rings, allowing the compressive load from the gland follower to move all of the rings equally. The obvious advantage is activating all the rings in the set, including the all important ring that sees the media to be sealed, while reducing overall friction on the shaft/sleeve. Good quality die-formed rings are usually provided as individual sets for each stuffing box, already ...

En règle générale, 70 % de l'usure de l'arbre due à la garniture tressée est causée par les premier et deuxième anneaux adjacents au fouloir de presse-étoupe. Pourquoi ? Imaginez que vous aviez 4 boîtes en carton pleines identiques à la suite l’une de l’autre et que vous poussiez sur la première, les 4 boîtes se déplaceraient comme une seule. La garniture ne réagit pas de cette façon, car la garniture tressée compressible doit se densifier suffisamment pour pousser sur l'anneau suivant et ainsi de suite. C'est la bague inférieure de la boîte à garniture qui doit être comprimée afin de produire une étanchéité efficace. Mais comment pouvez-vous faire passer la charge du presse-étoupe à cet anneau ? La réponse est d'utiliser des bagues de garniture moulées ou pré-comprimées, permettant à la charge de compression du fouloir de presse-étoupe de déplacer toutes les bagues de manière égale. L'avantage évident est d'activer tous les anneaux de l'ensemble, y c...

  5  important things to do  when replacing compression packing on a pump: By Jocelyn Vachon – Fluid Sealing Specialist and Packing Guru If you’re not doing these 5 things, you are increasing the chances of pump failure. Visual inspection of the packing rings:  As you remove the worn-out packing rings, inspect for unusual wear: this will reveal if a faulty element is causing damage and early failure (impregnated abrasive particles on the packing, torn areas, excessive wear on particular surfaces, over-compression, etc. Inspect equipment  for   excessive wear on the sleeve/shaft, excessive shaft eccentricity run-out, plugged water-line or limited pressure, bearings, etc. Install packing that meets the performance requirements : operating temperature, shaft speed, chemistry and potential abrasion. Install one packing ring at a time:  make sure packing is the right size (it should fit reasonably tight) and do not insert a spiral of packing into the stuffi...