Executing BTAHL7ReceivePipeline in an orchestration

Hi all:
 
I am trying to execute the BTAHL7 2X Disassembler inside an orchestration, the idea is to take a WCF Response with the HL7 content and convert it to a BTAHL7 message through the pipeline, this is what i am trying:

HL7Request =WCFResponse;HL7Request.LoadXml(string);
 
BTAHL7ReceivePipeline = Microsoft.XLANGs.Pipeline.XLANGPipelineManager.ExecuteReceivePipeline(typeof(HL7Pipeline), HL7Request);
 
HL7Request2.MSHSegment = new System.Xml.XmlDocument();
HL7Request2.BodySegments = new System.Xml.XmlDocument();
HL7Request2.ZSegments = new System.Xml.XmlDocument();
BTAHL7ReceivePipeline.MoveNext();
BTAHL7ReceivePipeline.GetCurrent(HL7Request2);
 
My problem is that i am getting

Object reference not set to an instance of an object error at BTAHL7ReceivePipeline.GetCurrent(HL7Request2);