A flow meter assembly having a longitudinal axis , the flow meter assembly , comprising: an upstream member comprising a first end , a second end comprising a first alignment receptacle and a second alignment receptacle, and a fluid passageway extending between the first and second ends ; a downstream member comprising a first end , a second end , comprising a third alignment receptacle and a fourth alignment receptacle, and a fluid passageway extending between the first and second ends ; and a throat member comprising a first end which comprises a first alignment pin and a second alignment pin, and a second end which comprises a third alignment pin and a fourth alignment pin, and a fluid passageway extending between the first and second ends , wherein the fluid passageway of the throat member comprises a minimum inner diameter portion configured to provide a restriction in a fluid flow passing through the flow meter assembly ; wherein the first end of the throat member is configured to be removably coupled to the second end of the upstream member such that the first alignment receptacle of the upstream member receives the first alignment pin of the throat member and the second alignment receptacle of the upstream member receives the second alignment pin of the throat member to axially align the upstream member with the throat member , and the second end of the throat member is configured to be removably coupled to the second end of the downstream member , such that the third alignment receptacle receives the second alignment pin of the throat member and the fourth alignment receptacle receives the second alignment pin of the throat member to axially align the downstream member with the throat member , and the first end of the throat member comprises an annular flange , the second end of the throat member comprises an annular flange , the second end of the upstream member (102 302) comprises an annular flange and the second end of the downstream member comprises an annular flange . an upstream member comprising a first end , a second end comprising a first alignment receptacle and a second alignment receptacle, and a fluid passageway extending between the first and second ends ; a downstream member comprising a first end , a second end , comprising a third alignment receptacle and a fourth alignment receptacle, and a fluid passageway extending between the first and second ends ; and a throat member comprising a first end which comprises a first alignment pin and a second alignment pin, and a second end which comprises a third alignment pin and a fourth alignment pin, and a fluid passageway extending between the first and second ends , wherein the fluid passageway of the throat member comprises a minimum inner diameter portion configured to provide a restriction in a fluid flow passing through the flow meter assembly ; wherein the first end of the throat member is configured to be removably coupled to the second end of the upstream member such that the first alignment receptacle of the upstream member receives the first alignment pin of the throat member and the second alignment receptacle of the upstream member receives the second alignment pin of the throat member to axially align the upstream member with the throat member , and the second end of the throat member is configured to be removably coupled to the second end of the downstream member , such that the third alignment receptacle receives the second alignment pin of the throat member and the fourth alignment receptacle receives the second alignment pin of the throat member to axially align the downstream member with the throat member , and the first end of the throat member comprises an annular flange , the second end of the throat member comprises an annular flange , the second end of the upstream member (102 302) comprises an annular flange and the second end of the downstream member comprises an annular flange . <EOS>