Part Number 4129B000-004 Valve Primary Heat Exchanger Bypa in stock with ready to ship. Get an instant quote for Honeywell Aerospatiale Inc part number 4129B000-004 by filling form below with your desired order quantity, targeted price and the expected order-fulfilment date. Get instant quote for 4129B000-004. Our dedicated account manager will get back to you within 15 minutes.