Peter, Do you mean slide valves? Barrie -----Original Message----- From: peter.chadwick@xxxxxxxxxxx Sent: Monday, March 19, 2012 2:23 PM To: modeleng@xxxxxxxxxxxxx Subject: [modeleng] Naive question I keep reading in all the books that flat valves and superheated steam don't go too well together. Why? I can't see it being down to port area...... Peter Chadwick Swindon ---------- This email is confidential and may contain information that is privileged and exempt from disclosure by law. If you have received it in error, please contact the sender immediately by return email and then delete it from your system; you should not copy it or disclose its contents to anyone. Emails are not secure and cannot be guaranteed to be error free as they can be intercepted, amended, lost or destroyed, or contain viruses. Anyone who communicates with us by email is taken to accept these risks. MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line. MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.