Home/Products/Valves, doors, controls

Valves, doors and controls: where the supply boundary sits

Name: Valves, Doors and Controls — Supply Scope
Brand: Shanke

If the supply scope is not set out line by line in the quotation, it becomes a change order during installation. This page states what belongs to the unit, what is installed on site, and how each item is priced.

Two groups, stated separately

The first group ships with the unit and is already in its price. The second is installed on site and priced per project. Mixing them into one price line is what produces arguments at commissioning.

Item	Group	Priced
Compressor, oil system, unit controls	Ships with the unit	Included in unit price
Liquid receiver, filter drier, sight glass	Ships with the unit	Included in unit price
Expansion valve, solenoid valve	Site installation	Listed separately
Isolation valves, strainers	Site installation	Listed separately
Control cabinet	Site installation	Listed separately
Cold room doors and fittings	Envelope	Listed separately
Piping, insulation, refrigerant charge	Site installation	Listed separately

Why the valve list is written out

A valve costs little; a wrong valve costs a room. This is the part of the scope most often left vague.

Item	If it is chosen incorrectly
Expansion valve	Unstable liquid feed, room temperature swings, hunting
Solenoid valve	Liquid migration back to the compressor on shutdown
Check valve	Hot gas migration, repeated restart trips
Filter drier	Moisture and debris reaching the expansion valve

Valves are specified by refrigerant, evaporating temperature and capacity, not by pipe size alone, which is why they are a separate line rather than an assumption.

Doors are the largest single source of heat gain

A door is not a fitting. It is an opening in the envelope that is used many times a day, and it is where most rooms lose their performance.

Door type	Used for	Note
Hinged door	Personnel access, small rooms	Simple seal, lower cost
Sliding door	Forklift access, high traffic	Heated frame required in freezers
Conveyor or strip door	Product transfer openings	Air movement control matters more than the seal
High-speed door	High-frequency traffic	Reduces both heat gain and defrost load

Door selection belongs to the envelope design, not to the end of the procurement list.

Supply scope questions

Does the unit price include valves?

The standard unit scope is listed above. Valves, control cabinets and doors are separate items, and the quotation shows which is which so the boundary is visible before the order is placed.

Who supplies the control cabinet?

It is quoted separately as part of the wider scope. Where a local panel builder is used, we provide the wiring schedule and the sequence of operation.

Can panels, units and doors come from one supplier?

Yes, and that is the normal arrangement. One manufacturer means one party responsible when a room does not hold temperature, instead of three suppliers disputing scope.

Send the room conditions

Product, room temperature, tonnage and daily throughput — enough to come back with a selection and an indicative price.

Email us WhatsApp