i will post the prices as soon as i get them i have called the company and ill receive a price list by mail

for those who cant open the pdf link above here is a html link...

http://www.tecnidro.com/idromembranaplastic.html

i am calling them tomorrow for prices ill let u know...

the valve i called a Diaphragmvalve

i just found this danish sales company they have some big valves for some really big launchers...
please let me know if these wont work for a tennisball launcher

http://www.dvt-dk.dana2.dk/data/images/110420b.pdf