THE NEED FOR HIGH VOLUME VALVES Seating of the Tire: The most important feature is to allow the tire to seat as quickly as possible. So the valve must allow high volume air flow. Presta valves by design are not high volume, hence users generally will remove valve core to pre-seat tire before final inflation. Sealant Injection: With tubeless wheels its common practice to use a liquid sealant in the tire, to prevent flats, these sealants have high viscosity so block traditional valves. This necessitates the need to remove a Presta/Schrader valve cores to inject the sealant.