The CL838 is available in the following models:

• CL838-1 – The CL838-1 has maximum inlet pressure of 150 PSIG and an outlet pressure range 6″ W.C. to 5 PSIG with the orifice size of 3/8″ through 1 3/8″
• CL838-2 – The CL838-2 has maximum inlet pressure of 150 PSIG and an outlet pressure range 1 PSIG to 30 PSIG with the orifice size of 3/8″ through 1 3/8″
• CL838D-1 – The CL838D-1 (Downstream Control) has a maximum inlet pressure of 150 PSIG and an outlet pressure range 6″ W.C. to 5 PSIG with closed throat and equipped for downstream control tap.  This unit is used when it is desirable to control the regulator from a downstream sensing point other than the regulator valve body outlet side.  All capacity curves are the same except no boost is experienced at the control point.  Orifice sizes 3/8″ through 1 3/8″
• CL838D-2 – The CL838D-2  has maximum inlet pressure of 150 PSIG and an outlet pressure range 1 PSIG to 30 PSIG.  All other facets of the CL838D-2 are the same as the CL838D-1 regulator
• CL838M-1 – The CL838M-1 is a regulator for monitor installation with closed throat and o-ring seal on the valve stem at the throat to assure positive downstream control when installed ahead of the operating regulator.  This unit provides an operating safety device which assumes control over the operating regulator when failure is sensed by the monitor control line.  The monitor regulator is set to take over control from the operating regulator with only a slight increase in outlet pressure.  It can be equipped with an orifice size ranging from  3/8″ through 1 3/8″ and outlet pressure ranges from 6″ W.C. to 5 PSIG and inlet pressures of 150 PSIG maximum
• CL838M-2 – All facets of this regulator are the same as the CL838M-1 except the range of the outlet pressures, which are from 1 PSIG to 30 PSIG