In Clayton v. Lienhard, 312 Pa. 433, 167 A. 321 (1933), our Supreme Court considered whether an automatic sprinkler system was an "annexation" and, thus, fell into the second class of chattels identified in Sheetz. The Supreme Court concluded that the sprinkler system fell into the second class of chattels. It reasoned as follows: The sprinkler system in the instant case must, we think, be considered as falling within the second class above described-a part of the realty for all purposes. It was installed in the original construction of the building; it was a permanent improvement which would pass upon a sale of the freehold; it was affixed so that it could not be removed without material injury to the building and damage to itself. By these criteria, the apparatus became realty as an integral part of the building. Id. at 437, 167 A. at 322.