Robco Expert

  Is it possible I have leakage because of a damaged flange? Flange failure: In a piping system, flanges are an essential element for ideal containment. The structural integrity of the junction should never be affected, however flange failure is a fairly uncommon problem but can be catastrophic. Flange failures are primarily due to: • Damaged flange surfaces or Improper Flange Facing, because the deeper serrations than specified will prevent the seating especially in metallic and semi metallic gaskets like spiral wound gaskets (please refer to previous blog entry entitled: Flange Surface Finish vs Gasket type ). • B uckling flanges: Excessive bending movements on flange s can loosen the bolting or distort the flanges and lead to leaks. This situation can also be produced by thermal s hock where the rapid temperature fluctuations can cause flanges to deform temporarily. • Non-parallel flanges: Improper flange face parallelism, causes uneven gasket compression, local ga...

What are Spray Safety Shields? Spray safety shields, are installed on pipe joints, these being the ‘weak points’ where leaks typically occur. For critical pressurised applications, they are the vital first line of defence to prevent fire, explosion and toxic release which would otherwise endanger plant and personnel. Prevent Spray-outs - Generally the most important requirement is to control the leak, create a safe release and thus avoid a dangerous spray-out, which would otherwise happen even at low pressure. Avoid oil mist formation - For certain oil & fuel applications, oil mist formation is just as hazardous as a spray-out. Furthermore, ill-fitting safety shields can actually create mist formation. Provide leak indication - It is important to identify leaks as quickly as possible, though the process will determine the urgency. For certain acid lines, some customers require that flanges must not be concealed. This is achieved using transparent shielding. Alternatively leak-indic...

Is there a rule of thumb to measure the proper amount of cooling water leakage , when using braided packing on rotary equipment (ex: pumps, agitators, mixers, etc.) ?  Jocelyn Vachon - VP B.Dev / Product Specialist In order for braided compression packing to seal and work properly on a dynamic equipment, water is injected through a flush line and distributed inside the stuffing box by a lantern ring. A small amount of this water will therefore leak out from the stuffing box.  The objective is twofold : A positive pressure of clean water has to be created inside the stuffing box, to prevent process fluid from entering the stuffing box To minimize frictional heat, by creating a hydrodynamic lubricating film between the stationary packing rings and the rotating shaft. This is a balancing act between how much compression is exerted on the packing rings set, to reduce to a minimum process fluid leakage versus limiting frictional heat. A...

One major reason your joints may be leaking... and it is not the gasket. There are a number of reasons that contribute to a seal joint failure, including weak bolt material, improper installation, inadequate bolting torque or poor flange design. Yet, if a joint fails and leaks, the immediate culprit will usually be the... gasket. Perhaps, a flange inspection would be the first analysis to do Flange face damage is an important parameter that may restrict a gasket to seal properly.  We need to take this into consideration when we analyze the sealing failure of a junction. Among flange face damages, we can find: Scratches: This type damage is narrow and elongated with sharp, shallow bottoms. However, depending on the force that created them, they can be deep. Frequently, this type of damage is created by a sharp object dragging across the flange face. These objects may include the bristles of a wire brush or a tool, such as a chisel. Gouges: These are wide and elongated with ...