Along with the manufacture of strainer screens and filters, the housing is also an important consideration; the following are a few of the features which require evaluation when specifying a strainer:
All GFSA products are supplied ready assembled and can be fitted directly into the process line. Many GFSA products are so compact they can be fitted into the process line without any further support or foundation. All larger units are provided with support legs and/or feet.
Ease of screen and basket removal is very important. GFSA products can be supplied with either bolted or quick-release closures, which require no special tools or skilled labour and provide the minimum of downtime. GFSA can also offer exclusive patent-protected safety devices to both bolted and quick release closures for maximum operator safety.
In today’s modern industrial plants and installations, space is limited and precious. This is particularly so on off-shore installations so the housing should not be unnecessarily bulky or tall.
Most GFSA products incorporate inlet and outlet connections which are in-line. Bends and sharp angles should be avoided and fluid flow areas must always exceed the inlet area. All sudden expansions and contractions within the unit must be carefully calculated to minimise internal pressure energy loss. GFSA products are designed and manufactured with all these criteria being strictly observed.
Strainer and Filter housings must be strong and robust in order to withstand the many loadings they may be subject to which may be either predictable or unpredictable. Such loadings may include:
- Internal and External Pressure
- Local Pipe Loads
- Cyclic Fluctuations
- Earthquake and Wind Loadings
- Explosion Loads
- Snow and Ice Loadings
- Motion Loads
- Overload and Shock Conditions
A common example in steam lines is where condensate collects at a low point in the system and becomes a ‘slug’ travelling at very high velocity down the pipeline. A slight change in direction can cause a tremendous shock which can severely damage the housing wall. In recent years there has been a tendency by certain manufacturers to thin down the walls of castings in order to save weight and reduce costs. However, this very often leads to unreliable castings, which often leak in service and provide much shorter life spans.
All GFSA products are designed with thicknesses which include allowances for corrosion, erosion and manufacturing tolerances, and far exceed the minimum required thicknesses as specified by international pressure vessel codes ASME VIII, PD 5500 and EN 13445. All pressure retaining products are PED compliant.