Section 402.205. Firm offers.

  An offer by a merchant to buy or sell goods in a signed writing which by its terms gives assurance that it will be held open is not revocable, for lack of consideration, during the time stated or if no time is stated for a reasonable time, but in no event may such period of irrevocability exceed 3 months; but any such term of assurance on a form supplied by the offeree must be separately signed by the offeror.

Although a bid for pipe did not meet the “firm offer" requirement, the facts pleaded and relied upon by the contractor to support its claim and to which the supplier responded in entering its defense gave rise to the doctrine of promissory estoppel. Janke Construction Co., Inc. v. Vulcan Materials Co. 386 F. Supp. 687 (1974).