8" Plastic Vent Cap

The PLASTIC MUSHROOM STYLE TANK VENT CAP, or tank breather cap, keeps out debris, insects, seeds, and rain while allowing tanks to properly vent. All plastic construction is corrosion proof.

All Plastic Tank Vent Cap tank breather cap is all plastic and therefore corrosion-proof. Allows containers to vent while screening out debris, airborne seeds, and insects. PVC body with polypropylene screen.

Prevents containers from collapsing under partial vacuum, or building pressure during filling. Mushroom style plastic vent cap prevents falling dirt from clogging the screen and prevents rain water from entering tank. These mushroom style breather vents are suitable for wash-down duty. Used for roof vent stacks, air intakes, venting equipment cabinets, exhaust pipes and more.

Available in any standard NPT fitting sizes 1/2" fitting size and larger - male thread, female thread or slip fitting. All sizes up to 6" are in stock. 8" Sizes are built to order so allow about two weeks lead time. 

See Link To Smaller Sizes: 1/2" to 4"

Screen size:

• Standard polypropylene mesh size is 17x17 strands per inch for sizes 2" and under, and 10x10 strands per inch for 3-6" sizes, and perforated PVC sheet for 8" size.
• 17 x 17 mesh complies with FDA regulations for potable water storage.

SPECIFICATIONS

• Material (housing)...................................PVC, schedule 40
• Screen mesh material............................ polypropylene
• Screen mesh size (2" and smaller).........17x17 mesh
• Screen mesh size (3-6")..........................10 x 10 mesh
• Screen mesh size (8").............................1/8" PVC with" 0.125" dia. holes
• Open area................................................40% (all sizes)
• Maximum temperature..............................150F (65C)

How much air flow the vent caps are capable of, is a common question. The amount of flow through the vent cap depends not only on the size of the vent cap, but on the pressure in the piping system or tank, the flowrate. The amount of resistance to flow introduced by the vent cap can be conveniently expressed as the pressure drop equivalent to a length of the same diameter pipe.

As an example, to determine the pressure drop of a 4" vent cap, table 1 shows the equivalent pipe length resistance is 30 ft. Looking at the chart 1, and selecting the top curve marked HP220, the volume of air for this curve is reduced from approximately 230 (extrapolated to zero pipe length) to 200 CFM at 30 feet.