If you have the correct size tap for the nipple you should go ahead and tap the hole out.
													
																	Pvc air cannon sprinkler valve. 
									
		
	
	
		
	
	
		
	
	
		
	
																	How to build an air cannon with a sprinkler valve. 
																	At 60 psi this d. 
																	This cannon is capable of shooting projectiles such as oranges or parts of a potato very far distances and at very high velocities. 
																	This instructable will teach you how to build an air cannon that can be triggered with a switch. 
															
													
									
		
	
	
		
	
	
		
	
	
		
	
																	Qev sprinkler valve air cannon pvc plug. 
																	Instead i will mount the nipple and blow gun trigger to the plug itself. 
																	It looks awesome and can kill a watermelon from. 
																	Drill a half inch hole into the center of the plug.