We describe the Valterra Replacement Seals and Hardware Kit # T1003-7VP as being intended for the "old style" 3-inch waste valves. This is also how they are described on the Valterra website.
The 9VP kit # T1003-9VP is for use with the Bladex type waste valves like # T1003DSPB. These seals are the same 3-inch size but have a slightly different profile. view full answer...