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AlpHa Measurement Solutions
10540 Rockley Road
Houston, TX 77099

(Toll Free) 800-522-7920
(voice) 832-456-4100
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Mark 7 Series For pH And ORP Applications (Hot Tap) TEXT SIZE: A A A    PRINT THIS PAGE   EMAIL THIS PAGE
 Hot Tap Assembly
Mark 7-S Mark 7-S
Mark 7-Z Mark 7-Z
Mark 7-K
Mark 7-K (Kynar)
  • Safe Operation
    Mark 7 assemblies can be safely removed and replaced under pressure without process shutdown. Electrode o-ring arrangement seals the electrode from leaking, even in the event of breakage.
  • Low Cost Electrode Replacement
    The 3-in-1 Mark 7 electrode houses the measuring, reference, and automatic temperature compensator (ATC) to reduce inventory and maintenance downtime. A variety of styles are available to optimize electrode life.
  • Top-Entry Electrode Installation
    The electrode is removable through the junction box; no tools or disassembly required.
  • Quality "Built In"
    All Van London Co. (aka Van London pHoenix Co.) assemblies and electrodes meet strict, documented quality specifications, followed through each step of the manufacturing process.
  • Convenient Electrical Connections
    The junction box houses all electrical connections (including an optional preamplifier) so that the analyzer may be located in a friendly environment.
  • Custom Fabrication
    Several other materials and sensor styles are available for customer-specified requirements
The Mark 7 insertion assemblies permit continuous pH or ORP monitoring in pressurized vessels or lines. Specifications are for mounting onto a weldalet, a pipe tee or flange. To reduce the maintenance downtime required, electrode connections terminate inside an explosion-proof junction box which houses the preamp as well.
Originally marketed for paper mill stock pulp applications, the "Modified Tip" (illustrated above as Mark 7-Z) is available in any style of Mark 7 sensor for processes where accumulation around the sensing tip is a concern. The Modified Tip creates a low profile guard so that it protects the electrode bulb and reference junction. With this design, the process flow actually aids in the cleaning action.
Measuring Types:   Platinum Band - For ORP measurement (0-130°C)
GXV - Multi purpose pH glass formulation 0-14pH
Antimony - For pH measurements in HF applications, 2-7pH (0-80°C)


P65Warning WARNING: Cancer -


Reference Types:   SPR™ - Double junction, solid polymer reference (0-130°C)
Electrode Materials:   Glass and ceramic (platinum for ORP)
Housing Materials:   Ryton® (standard)
*O-ring Materials:   Viton® (standard)
  Mark 7-S Mark 7-K Mark 7-Z
Tube Material: 316SS Kynar® and Viton® 316SS
Gland Fitting Material: 316SS, Viton®, & Nylon Kynar® and Viton® 316SS, Viton®, & Nylon
Ball Valve Material: 316SS and Teflon® Kynar® and Teflon® 316SS and Teflon®
Restraint Cables: Yes Yes Not required
Tube Diameter: ¾" 1" ¾"
Process Connection: 1" MNPT 1¼"MNPT 1" MNPT
Maximum Pressure: 150 psi 100 psi 150 psi
Standard Adjustable Insertion: 7" (standard) 6" (standard) 7" (standard)
Total Height (Retracted): 25" 25" 25"
Junction Box (All Models): Class I, Division II, Group D classification; NEMA 4X anf 7B ratings
Other sensor materials include Hastelloy C, Titanium, and Alloy 20. Flange assemblies are optional. Consult the factory for availability.
Combination pH Electrode
Hot Tap Combination pH Electrode
  • Mark VII assemblies and electrode cartridges are sold separately. To build your own electrode part number, first determine the electrode style required and then replace x's with selections listed in the drop-down menu below.
  • Call the factory if application assistance is required. Conversion information is readily available for quick replacement of existing installations.
    MK7x - x xx x x x x : Mark VII Assembly
|   | | | | | |
|   | | | | | Special Options
|   | | | | | 0 No options (standard)
|   | | | | | 1 High Tempurature - Peek
|   | | | | Ferrule Material
|   | | | | 1 Split Stainless Steel/Nylon (standard)
|   | | | | 4 Kynar® (for Kynar® sensors only)
|   | | | O-ring Material
|   | | | 1 Viton® (standard)
|   | | | 3 Kalrez®
|   | | Ball Valve
|   | | 3 1" 1-piece (standard)
|   | | 4 1" 3-piece (Hastelloy C)
|   | | 5 1¼" 3-piece (standard Kynar® only
|   | Maximum Tube Insertion Depth
|   | 06 6 inches (standard for Kynar®)
|   | 07 7 inches (standard for 316SS)
|   Material of Construction
|   1 316SS (standard)
|   2 Kynar®
|   4 Hastelloy C
           Assembly Style
           S Standard
           Z Quick Disconnect Modified Tip


9210038 4.00pH, 7.00pH and Deionized Water rinse (1 pint each)
9210037 4.00pH, 7.00pH and 10.00pH (1 pint each)
9210039 7.00pH, 10.00pH and Deionized Water rinse (1 pint each)
9210079 Anti-fouling solution to reduce electrode-coating problems
9210008-125 Electrode storage solution KCl/4.00 pH buffer (125 ml)
2010655-XX FBNC/SL to Hanked (tinned)
2010730-XX FBNC/Male Molex to Hanked (tinned)
2010681-XX FBNC/Male Molex to MBNC/Hanked (tinned)
XX - denotes lead length in even feet
Kynar is a trademark of Pennwalt Corporation.
SPR is a trademark of Van London Co. (aka Van London pHoenix Co.)
Viton, Teflon, and Kalrez are trademarks of E.I. Dupont de Nemours & Co.