Purpose

Steam piston pumps are designed to operate on both saturated and superheated steam with temperatures up to 573 K (300 °C), in both stationary and mobile conditions, for pumping oil and petroleum products, liquefied hydrocarbon gases, fresh and seawater, and other liquids similar in density, viscosity, and chemical activity, with temperatures up to 673 K (400 °C), depending on pump design. The maximum mass concentration of solid particles in the pumped medium must not exceed 0.2%, and the maximum particle size should be no more than 0.2 mm.

These pumps provide stepless regulation of flow and outlet pressure within 25 to 100% of the nominal value by adjusting the inlet steam pressure. Regulation can affect either flow or pressure independently, or both simultaneously.

Design Types:

•  PDG: Direct-acting, dual-piston, double-acting, horizontal
•  PDV: Direct-acting, dual-piston, double-acting, vertical

By Application, Pumps Are Manufactured in the Following Versions:

•  N — For dark petroleum products with kinematic viscosity from 0.008×10^-4 to 8×10^-4 m2/s (0.008 to 8 cSt), temperatures from 273 K to 493 K (0 to 220 °C)
•  NSh — Sludge type, for dark petroleum products (same viscosity/temperature), with up to 2% solid content and particles up to 8 mm
•  NG — For petroleum products with temperatures up to 673 K (400 °C)
•  NGSh — Sludge type, for same as above, up to 2% solids, particles up to 8 mm
•  G — For liquefied hydrocarbon gases with density from 480 to 700 kg/m3 and temperature from 243 K to 313 K (-30 to +40 °C)
•  Kh (X) — For benzene products, coal tar, and dark petroleum products with viscosity 0.008 to 8 cSt, up to 393 K (120 °C)
•  S — Marine type, for fresh/seawater and similar liquids, viscosity 0.008 to 8 cSt, temperatures from 278 K to 393 K (5 to 120 °C). Pumps with flow >100 m3/h also handle gasoline at 273 K to 303 K (0 to 30 °C)
•  O — General industrial use: fresh water, dark petroleum products, similar fluids, 0.008 to 8 cSt, 278 K to 378 K (5 to 105 °C)

Climatic Versions:

•  N, NSh, NG, NGSh, G, Kh, O: UHL4, T5
•  S: UHL4, and for marine/tropical use — OM5. Operation is allowed in placement categories 2 and 3 with temperatures no lower than -15 °C.
  

Explosion safety, reliability, smooth flow/pressure regulation, and simple construction and maintenance make these pumps irreplaceable in certain industries. PDG and PDV types are especially useful where cheap steam is available, or electricity is unavailable or unsafe to use (e.g., due to fire safety).

Design
 The pump consists of two main parts: steam and hydraulic. The steam section drives the mechanism; the hydraulic part performs the pumping. In pumps with flow rates up to 60 m3/h, each hydraulic cylinder chamber includes one suction and one discharge valve. For pumps >100 m3/h, each chamber has two suction and two discharge valves.

Designation Example:
 PDG 25/45 B-N-UHL4 TU U 29.1-38136281-003:2012
 Where:

•  PDG — Pump type: Steam piston, dual-cylinder, horizontal (PDV = vertical)
•  25 — Nominal flow rate (m3/h)
•  45 — Outlet pressure (kgf/cm2)
•  B — Modernization index (A = first, B = second, C = third)
•  N — Application type (e.g., N, NSh, NG, NGSh, G, Kh, O, S)
•  UHL — Climate version (UHL, T5, OM5)
•  4 — Installation category
•  .. — Technical specification number
  

Pump Specifications Table