I can't remember where I found them, but here are the cheats for Pipe 2 Blast Chamber:

***Pipe 2 Blast Chamber Easter Eggs
When you use an easter egg or cheat, you cannot post the score from that game to the score charts, or go past level 14.
Type the following at the game's main menu before starting a game:
457scroller: makes all levels sidescrollers
778Crazy: makes you have to hammer pipes many more times
699hit: causes thugs to have to be hit more before they die
123special: start game with more special items
fastWalk: increases walking speed on sidescroller levels
superjump: extreme airtime on sidescroller levels
***Pipe 2 Blast Chamber Cheats
The following cheats are to be used during actual game play:
Type 779ammo while a toolbox is active for unlimitted ammo.
Type 889 at a toolbox for unlimitted welding kits.
Type fl at stairs to get a flame thrower. Press F on a steam level to use it and destroy the closest barrel or sewer.
While at a trashcan, press spacebar for an interesting message.
Type Dan while a thug is active to get a new gun.
Type 999 while at the transition between levels to have the next boolbox unlocked automatically for you.
Type off while you are supposed to be twisting the water valve to shut off the pipe water.
Type 399 while at a trashcan, then press S on any pipe or electricity level to create stairs there.
Type 2279 while the game is paused to get a ton of flashlights, which have the added effect of destroying electricity on electricity levels.
Type 70grenade on the first pipe of a pipe or electricity level to cause your toolbox to have just one pipe, and pipes only require one hammer hit.